Pressure vs. Suction/Vacuum Brake Bleeders

[gerryvz]

PelicanParts is having a 15% off sale on Motive Power Bleeders and accessories.

If you do get one, I HIGHLY recommend the "Black Label European" model which works excellently on our cars.

You will need to use the code MOTIVE15 to get the discount.

URL: http://www.pelicanparts.com/promos/...ail&utm_term=0_e247719183-3891be9d7c-70067005

No affiiation, etc.

I purchased my Motive stuff through Amazon, so I don't know if their prices are better, but it's worth comparing against the discounted PelicanParts prices.

Must-have DIY tool - makes bleeding brakes on the .036 and 126.045 a snap !! Also ... Motives are a tool that the chicks really dig. The 589 equivalent of the gray door switches.

Cheers,
Gerry

 

[gsxr]

Re: Sale on Motive Power Bleeders

I would also recommend getting the catch bottles, which are sold in sets of 2. These are VERY useful when bleeding.

 

[Maui]

Love my Motive bleeder. I use a beer bottle for a catch bottle but I like the idea of the Motive bottles.

 

[gerryvz]

Re: Sale on Motive Power Bleeders

I have used clear plastic water bottles in the past as catch bottles, but recently purchased a set of Motive bleeder bottles on Amazon. Have yet to use them, but will be doing so in the near future on my SEC, and my G-wagen.

 

[gsxr]

Re: Sale on Motive Power Bleeders

Tip: Mark the sides of the catch bottles in mL increments so you know roughly how much has been extracted from each caliper (assuming they do not have graduations in the plastic already). If using a permanent marker, put clear packing tape over the marker, otherwise brake fluid will erase what you wrote. Don't ask how I know...

 

[samiam44]

Re: Sale on Motive Power Bleeders

Note,

While many ppl use this product successfully, it will not generate the pressure per MB's instructions for pressure bleeding.
I'll let Klink fill in the details.


M

 

[gsxr]

Re: Sale on Motive Power Bleeders

I've had no issues using 30psi but I do not have a Motive bleeder. What is the max working pressure the Motive can provide? I can't seem to find the spec in the FSM.

 

[Maui]

Re: Sale on Motive Power Bleeders

It doesn't take 30psi to bleed brakes. I have no problems even at 15psi getting a good bleed. The Motive gauge appears to go up to 30psi but I have never pumped mine up that high.

 

[gsxr]

Re: Sale on Motive Power Bleeders

Models with ASR need more pressure than without ASR. The bleeder I have uses a tire as the air source and I leave the regulator maxed so it's usually 30-32psi or so.

Could be 15psi is about the minimum pressure for ASR, but I'm not certain. Klink?

UPDATE: The FSM specifies 2 bar (29psi) pressure for bleeding. See job 42-0010, page 2, screen shot attached below.

 

[gerryvz]

Re: Sale on Motive Power Bleeders

I have bled ASR and non-ASR brakes (560SEC and E500) in the 25-30 PSI (indicated) range with the Motive power bleeder with no problems. I've done 20-25 absolutely no issues with non-ASR. ~20 is the minimum that I "pump it up" to.

 

[Klink]

Re: Sale on Motive Power Bleeders

Fifteen PSI/1bar is enough for any bleed job on these cars. I'd never go more that 25 at risk of exploding the fluid reservoir...

 

[gsxr]

Re: Sale on Motive Power Bleeders

Fifteen PSI/1bar is enough for any bleed job on these cars. I'd never go more that 25 at risk of exploding the fluid reservoir...

LOL. Yep, good point... keep an eye on the rubber caps atop the reservoir. If perchance they are old and cracked... you can make a VERY impressive mess. As always, don't ask how I know.

FWIW, I've not had any issues with ~30psi pressure but if Klink says 15psi is adequate, probably best to stick with the safer pressures.

 

[nocfn]

Re: Sale on Motive Power Bleeders

I did mine a skosh over 15, no trouble.

 

[Klink]

Re: Sale on Motive Power Bleeders

The specified pressure is 2 bar/30 psi, but that's too high for me unless I knew I had a brand-new reservoir that isn't going to split open like a dropped watermelon and spray brake fluid everywhere. No, I mean absolutely EVERYWHERE. A crack in that plastic with 30, or even 15 psi on it creates a powerful splashy long distance spray that is mind-boggling in its ability to soak the car in question and half of the other cars in the shop. It literally ricochets off of whatever it strikes, then ricochets off the next thing it strikes, ad infinitum. Like Tommy Boy said, seen it 100 times...

 

[DerFuror]

Power Bleed on Me

The specified pressure is 2 bar/30 psi, but that's too high for me unless I knew I had a brand-new reservoir that isn't going to split open like a dropped watermelon and spray brake fluid everywhere. No, I mean absolutely EVERYWHERE. A crack in that plastic with 30, or even 15 psi on it creates a powerful splashy long distance spray that is mind-boggling in its ability to soak the car in question and half of the other cars in the shop. It literally ricochets off of whatever it strikes, then ricochets off the next thing it strikes, ad infinitum. Like Tommy Boy said, seen it 100 times...

That would truly suck. Can't happen with a "Puller"-style bleeder like this one which attaches to the bleed screw.

 

[Klink]

Re: Sale on Motive Power Bleeders

Yes. For cars like these, the suction style works just fine.

 

[gerryvz]

Sale on Motive Power Bleeders

That would truly suck. Can't happen with a "Puller"-style bleeder like this one which attaches to the bleed screw.

View attachment 54349

I had & used a Griot's bleeder. Didn't work nearly as well nor effectively as the Motive.


Sent from my iPhone using Tapatalk

 

[gsxr]

Re: Sale on Motive Power Bleeders

Years ago I used suction-style bleeders for older cars without ABS or ASR. They worked, but were generally a PITA as they always pulled air around the bleeder screw threads so the bubbles never stopped. Sure, you can try to seal up the threads but that will be a messy proposition.

More importantly... my understanding is that the suction/vacuum style does not work properly on cars with ASR. That is why you cannot manually bleed by pumping the brake pedal. The suction style may work with ABS only (non-ASR) but I would be surprised if a proper flush/bleed could be accomplished with ASR via suction/vacuum. Something about valves in the ASR unit that require pressure to push fluid through them...? If this is correct, I would not recommend use this for any E500E, which all have ASR as standard equipment.

 

[samiam44]

Re: Sale on Motive Power Bleeders

If the suction tools work on asr/abs cars. I have a vacuula which I loved in the 90s.
Dave just remove the bleed screw and put grease on the threads and start bleeding... no bubbles. Besides, most of the time I'm changing fluid- color change and not bubbles. I ussually go a round, try the pedal and go around a second time.

Last 3 MB's I've done at a Tech session day at a dealership or independent.

Michael

 

[Trae]

MODERATOR EDIT: Copied this post from HOW-TO thread (here) as a reference:

Just bought this from Uncle Kent. Will let you know how it works.

Pressure Brake Bleeder

I have had this bleeder since 2019, so about three years, and have used it on my entire fleet.

BUT, now I have to report that every fitting is leaking. The yellow depressurization valve, screw on fitting, and even the catch bottle all leak.
This is after I was very careful to clean everything with denatured alcohol after every job.

Pressure Brake Bleeder | Slick D.I.Y. Hardware Product | MercedesSource.com

mercedessource Product - As of Jan. 2020 this pressure tank can now perform a cooling system pressure leak test as well . Kent's 2-in-1 invention. See below to purchase the pressure testing cap. When used for bleeding or flushing your brake system, a single person can do a rapid fluid flush! No...

mercedessource.com

 

[gsxr]

Sorry to hear that, Trae! I'm guessing the materials are not sufficiently resistant to brake fluid.

If it can't be successfully repaired, I haven't heard any complaints about the Motive kit:

https://www.ecstuning.com/b-motive-parts/european-power-bleeder/motivepb/

I have owned an old version of the Speedi-Bleed kit for probably 15-20 years and it has been mostly trouble-free, and completely leak-free. The pressure gauge no longer reads accurately but I check tire pressure before & after use, and the pressure isn't critical as long as it's in the 25-30psi range. I use Motive catch bottles, which have also worked well. Speedi-Bleed used to be a lot more expensive, something closer to $150 for a Euro kit IIRC, and their "master" kit with multiple adapters was $200+? I forget the exact numbers. The price probably scared away most DIY'ers. I wish the reservoir was larger, but it holds enough to fully bleed any W124/W210 brake system. The current master/complete kits with multiple adapters are ~$300 (link).

Speedi now has a different Euro version but the basic design & concept is the same. The quick-connect fitting at the reservoir adapter also allows the hose to spin freely, no twisted hoses. I haven't checked prices elsewhere, but direct from the mfr it's on sale for $90 for "Pro" kit with case, or $68 for "DIY" kit with minor design changes and without case. NO free shipping, add ~$20 for standard shipping. Speedi also sells a full range of replacement parts to repair your old kit if something breaks or leaks.

$150 $90 "Pro" kit + $20 shipping:

K400 European Brake Bleeder Kit

Perform a complete bleed or fluid flush on your European model vehicle in under 20 minutes. Discover the Speedi-Bleed difference.

www.speedibleed.com

$113 $68 "DIY" kit + $20 shipping:

K400B European Brake Bleeder Kit

Bleeding the brakes on your European model vehicle just got a whole lot easier. Find out how!

www.speedibleed.com

I suspect this may be a perma-sale, but I'm not sure.

 

[luckymike]

MODERATOR EDIT: Copied this post from HOW-TO thread (here) as a reference:


I have had this bleeder since 2019, so about three years, and have used it on my entire fleet.

BUT, now I have to report that every fitting is leaking. The yellow depressurization valve, screw on fitting, and even the catch bottle all leak.
This is after I was very careful to clean everything with denatured alcohol after every job.

Pressure Brake Bleeder | Slick D.I.Y. Hardware Product | MercedesSource.com

mercedessource Product - As of Jan. 2020 this pressure tank can now perform a cooling system pressure leak test as well . Kent's 2-in-1 invention. See below to purchase the pressure testing cap. When used for bleeding or flushing your brake system, a single person can do a rapid fluid flush! No...

mercedessource.com

I wonder if the denatured alcohol affected the seals?

 

[gsxr]

FWIW, I wipe mine dry with paper towels but don't use any other cleaning fluids. Not sure what the preferred method is.

 

[Trae]

Still time to cancel Motive. . .do you like Speedy Bleed better?

 

[gsxr]

Still time to cancel Motive. . .do you like Speedy Bleed better?

I've never used the Motive, but a LOT of people have had good results using it over many years.

Speedi uses a tire as the pressure source, no need to pump, and the reservoir is smaller. But the quick-connect fitting should allow the hose to rotate freely.

Motive has a reservoir twice the size (which is nice, but not necessary), requires manual pumping (not sure how often this is needed during the bleed process), and appears to have a screw-on fitting where the hose could get twisted? Maybe some Motive owners could comment.

Photo of the Motive adapter - the hose won't rotate as the cap is threaded on, or as the 2 brass fittings are screwed together.

I like the Speedi better, but I dunno if it's worth paying double for it...

 

[Trae]

Motive is cancelled until I have time to compare the two.

 

[masayoshi]

I had a hose burst while using Motive, I used it for about 5 years and would recommend anyone using Motive to have it checked before use.

 

[geraniumtr]

Guys, I’ve used a Motive bleeder for a few years without issue. Have done my E320, 2 Volvos and my new to me Mini Countryman with no problems. Dave is correct that the cap is fixed to the hose so you do have to keep it unkinked by moving the tank around. Not a big deal really. The E320 requires 2 bar pressure which is almost at the maximum for my base model bleeder so I pump up the pressure after each wheel is bled. Takes less than a minute.

Instructions say to clean using denatured alcohol which is what I do. You can buy a can at your favorite big box hardware store. I’m careful how I store the hose, making sure it’s not kinked or twisted.

Hope this is helpful.

Peter Weissman

 

[TerryA]

Question: Does the Motive bleeder come with the correct adapter to attach to the Master Cylinder Reservoir? OR is that an Extra Cost attachment?

 

[geraniumtr]

Terry, the model I bought was for European cars so yes it came with the correct size cap to fit the master cylinder. Other caps are available. Maybe the more expensive models come with several caps but you’d have to check.

Peter

 

[TerryA]

Thanks Peter, That’s good to know. I’m only interested in a unit that would fit my 500E without having to purchase an additional adapter.

 

[geraniumtr]

Terry, check Amazon, model 0100. $53 cost. That’s what I have but max. pressure is 30 psi or 2 bar. OK for my non ASR E320 but not sure if the E500E needs higher pressure to bleed properly.
I’m sure Dave or Gerry know the FSM specification.

Peter

 

[gsxr]

30psi is all you need! Klink doesn't recommend going beyond that... and use less for non-ASR cars to reduce the risk of unexpected leaks.

 

[LWB250]

I store the hose with the reservoir cap for my Motive bleeder upside down and hanging on a wire shelf. I thread the hose through the wires on the shelf and let the cap straddle the wires. I put the cap in a small sandwich baggie so dirt and dust can't get into it.

Keeps the kinks out.

Dan

 

[Jlaa]

Sorry to hear that, Trae! Im guessing the materials are not sufficiently resistant to brake fluid.

If it cant be successfully repaired, I havent heard any complaints about the Motive kit:

https://www.ecstuning.com/b-motive-parts/european-power-bleeder/motivepb/

I have owned an old version of the Speedi-Bleed kit for probably 15-20 years and it has been mostly trouble-free, and completely leak-free. The pressure gauge no longer reads accurately but I check tire pressure before & after use, and the pressure isnt critical as long as its in the 25-30psi range. I use Motive catch bottles, which have also worked well. Speedi-Bleed used to be a lot more expensive, something closer to $150 for a Euro kit IIRC, and their master kit with multiple adapters was $200+? I forget the exact numbers. The price probably scared away most DIYers. I wish the reservoir was larger, but it holds enough to fully bleed any W124/W210 brake system. The current master/complete kits with multiple adapters are ~$300 (link).

Speedi now has a different Euro version but the basic design & concept is the same. The quick-connect fitting at the reservoir adapter also allows the hose to spin freely, no twisted hoses. I havent checked prices elsewhere, but direct from the mfr its on sale for $90 for Pro kit with case, or $68 for DIY kit with minor design changes and without case. NO free shipping, add ~$20 for standard shipping. Speedi also sells a full range of replacement parts to repair your old kit if something breaks or leaks.

$150 $90 Pro kit + $20 shipping:

K400 European Brake Bleeder Kit

Perform a complete bleed or fluid flush on your European model vehicle in under 20 minutes. Discover the Speedi-Bleed difference.

www.speedibleed.com

$113 $68 DIY kit + $20 shipping:

K400B European Brake Bleeder Kit

Bleeding the brakes on your European model vehicle just got a whole lot easier. Find out how!

www.speedibleed.com

I suspect this may be a perma-sale, but Im not sure.

View attachment 154383

@gsxr, Thanks for this - I am intrigued with the "K400B Euro Brake Clutch Bleeder Kit".

@RicardoD was super gracious to help me with a clutch slave cylinder project this weekend and we used his wonderful Motive bleeder. My sport beetle requires that the bleeder be used WET (push fluid into the brake fluid reservoir, not air) because the design of the sport beetle makes it such that if you try to bleed the clutch dry, you will introduce air into the system. Don't ask me how we found out the below nugget of advice.



Anyways after using the Motive, I realized that I:

• Do not need a hand pump - I could just using my 18v battery operated tire inflator
• Would like a way to release the air pressure (depressurize the bleeder) before unscrewing the cap to the brake fluid reservoir
• Would prefer a smaller bottle - do not need the big container that the Motive uses.

For the K400B, are you able to depressurize the air in the bleeder with the knob/pressure-regular setup?
Also, if I want to power the K400B with my 18V tire inflator, Would I just use / make up a short section of hose with Schrader valves on both ends to interface between the K400B and the Ryobi inflator? Or is there a better way? Thanks.

 

[gsxr]

For the K400B, are you able to depressurize the air in the bleeder with the knob/pressure-regular setup?

Jlaa, when you disconnect the source air hose from the tire, this depressurizes the bottle without any mess. Then you can disconnect everything safely. When bleeding brakes, I time it so the bottle is empty and the M/C reservoir is not 100% full, which reduces the mess even more. Otherwise you have to suction/siphon some clean fluid out of the M/C reservoir when you're done.

Also, if I want to power the K400B with my 18V tire inflator, Would I just use / make up a short section of hose with Schrader valves on both ends to interface between the K400B and the Ryobi inflator? Or is there a better way? Thanks.

I wouldn't bother. Use a tire as the source, this also ensures you never have more than ~35psi present. When complete, use your 18V inflator to pump up the tire. It would be difficult to connect the inflator directly, and I'm not seeing the ROI for this mod?

 

[RicardoD]

@Jlaa having bled my clutch today (on my 964) after our lessons learned from yesterday, at 25psi of pressure in the bleeder, it was very easy to unscrew the large cap on the bleeder. It is not that bad to pump up to 25psi. Just keep it simple (but knowing you, you will create the ultimate Motive Bleeder mod, and I will await the parts list when you have this all figured out).

EDIT: I think these two 1/4" NPT bits will work to get the setup you want Jlaa. Just put them behind the pressure gauge on the Motive bleeder. Then you need a battery powered pressure pump to slowly raise the pressure in the Motive bleeder. I wouldn't hook up 110 psi shop air and blow up the system.



T- fitting.

 

[Jlaa]

For the [SppediBleed] K400B..., if I want to power the K400B with my 18V tire inflator, Would I just use / make up a short section of hose with Schrader valves ...

For what is worth, @gsxr, I had a discussion with the distributor of Speedibleed (Hi-Lo Distributors in Canada) and they are willing to put a Shrader valve on the Speedi Bleed in place of of the tire thumbtack nozzle. However, after looking at the price some more, it seems too high. The Speedi Bleed is a few dollars more than the Motive as they charge for shipping, and, the reservoir could be bigger.

@Jlaa having bled my clutch today (on my 964) after our lessons learned from yesterday, at 25psi of pressure in the bleeder, it was very easy to unscrew the large cap on the bleeder. It is not that bad to pump up to 25psi. Just keep it simple (but knowing you, you will create the ultimate Motive Bleeder mod, and I will await the parts list when you have this all figured out).

EDIT: I think these two 1/4 NPT bits will work to get the setup you want Jlaa. Just put them behind the pressure gauge on the Motive bleeder. Then you need a battery powered pressure pump to slowly raise the pressure in the Motive bleeder. I wouldnt hook up 110 psi shop air and blow up the system.

View attachment 161129

T- fitting.



[ATTACH type=full alt=Screenshot 2023-02-05 at 10.28.28 PM.png]161128[/ATTACH]

[ATTACH type=full alt=Screenshot 2023-02-05 at 10.28.54 PM.png]161127[/ATTACH]

RIGHT!!! Without a Motive in hand (I still need to get one --- Amazon prices are up above $90 for the "black" but the ebay prices are still in the 80s..) I need to determine if that fitting on the tank there is an 1/4" or 1/8" NPT.

I also thought about finding a way to reduce the worst part of the messiness that occurs when pressurizing wet-style..... When one is done bleeding and then depressurizes the bleeder and unscrews the cap on the brake fluid reservoir, the reservoir is full to the brim with brake fluid and one must use a baster to suck out fluid manually with a couple drips here and there.

That when I ran across this:



from here: The Making of the Inexpensive Brake Pressure Bleeder - BMW E36 M

Do you see that little section of copper tubing under the cap? That will automatically siphon out the brake fluid to the level of the copper tube once the system is depressurized! I need to think about how to modify a Motive with that.....

 

[gsxr]

For what is worth, @gsxr, I had a discussion with the distributor of Speedibleed (Hi-Lo Distributors in Canada) and they are willing to put a Shrader valve on the Speedi Bleed in place of of the tire thumbtack nozzle. However, after looking at the price some more, it seems too high. The Speedi Bleed is a few dollars more than the Motive as they charge for shipping, and, the reservoir could be bigger.

If there was a larger price delta, I would agree. But the Speedi has some advatages/features that, IMO, make it worth the small premium in cost. As noted above, although the Speedi reservoir is small, it does hold enough to complete a fluid change on all 124/210 chassis without having to refill the reservoir. And, I like not having to worry about reservoir pressure with Speedi... connected to a tire, you never have to pump up the reservoir during the bleed/flush process. Don't forget there have been some reports of Motive leaks after a few years; I haven't heard of any with Speedi, although arguably far fewer people use Speedi.

I also thought about finding a way to reduce the worst part of the messiness that occurs when pressurizing wet-style..... When one is done bleeding and then depressurizes the bleeder and unscrews the cap on the brake fluid reservoir, the reservoir is full to the brim with brake fluid and one must use a baster to suck out fluid manually with a couple drips here and there.

You don't want to end the bleeding / flush process with the reservoir completely full, for obvious reasons. Over the years, I learned to adjust my bleed/flush process so the reservoir would be right at the MAX mark when complete and depressurized. No siphoning needed afterwards, no need to top off either. Should be possible to do this with Motive also, if you pour in the appropriate amount of fluid in the bottle.

That when I ran across this: from here: The Making of the Inexpensive Brake Pressure Bleeder - BMW E36 M

Do you see that little section of copper tubing under the cap? That will automatically siphon out the brake fluid to the level of the copper tube once the system is depressurized! I need to think about how to modify a Motive with that.....

Using an appropriate bleed process, this modification is unnecessary.

 

[Jlaa]

You dont want to end the bleeding / flush process with the reservoir completely full, for obvious reasons. Over the years, I learned to adjust my bleed/flush process so the reservoir would be right at the MAX mark when complete and depressurized. No siphoning needed afterwards, no need to top off either. Should be possible to do this with Motive also, if you pour in the appropriate amount of fluid in the bottle.

Having the bleed process end at the MAX mark when depressurized without turkey baster sucking is only possible if you bleed using the dry method though right? If you are bleeding using the wet method because your car has a weird dual chamber dual pickup arrangement for clutch/brakes, then you always end up w too much fluid…..no?

 

[gsxr]

Having the bleed process end at the MAX mark when depressurized without turkey baster sucking is only possible if you bleed using the dry method though right? If you are bleeding using the wet method because your car has a weird dual chamber dual pickup arrangement for clutch/brakes, then you always end up w too much fluid…..no?

I honestly don't understand the wet/dry methods.

High-level summary of my process is: remove old fluid from reservoir, completely fill reservoir with clean fluid (~0.25L), fill the bottle with remaining ~0.75L, release SP port, pressurize, extract ~120mL from each caliper, start engine & open SP port, and close the SP port just as an air bubble appears on top of fluid in the reservoir. When the precharge pump shuts off 20-30 seconds later, level is at MAX, bottle is empty, and everything is peachy.

I have NO idea how this may affect vehicles with a multi-chamber reservoir that also feeds a clutch slave cylinder. However, all the 124/210 reservoirs have dual chambers, to ensure a loss of fluid in either front or rear will not cause a loss of braking power in the other half. What you describe may be unique to Superbeetles? It's not an issue with 80's through 00's Mercedes.

 

[RicardoD]

Jlaa,

If you do it the right way, as I did yesterday, you do NOT end up with a reservoir filled to the brim. The motive bleeder MAINTAINS the level that you started with (as long as you depressurize at the motive bleeder tank side). So you are trying to solve a problem that doesn't exist with the "wet style" if you do it properly. It worked perfectly for me yesterday.

The Schraeder valve idea is just the super lazy man's way of pressurizing the system and then releasing the pressure in the bleeder tank via the same Schaeder valve.

(Now let's talk what happens when you do it wrong and unscrew the red Motive reservoir cap while still pressurized. All the positive pressure in the bleeder tank forces all brake fluid in the hose into the reservoir causing a huge mess. That is why you relieve pressure in the bleeder tank first and the brake fluid in the clear hose flows in the other direction back into the bleeder tank.)

 

[RicardoD]

But if course if you are not using EXACT amounts of fluid, then when you are done and depressurize the bleeder system, you end up with fluid at the very very top of the reservoir and have to use a baster to suck out the excess fluid such that the fluid level goes down to the max level.

@Jlaa you are wrong here. Used properly the Motive bleeder maintains the level in the car's reservoir at the exact level you started at. It will never add "extra" fluid to the reservoir if you bleed the pressure at the Motive tank first. That is the genius of the system. It maintains the level in the reservoir that you started with.

As you bleed at the clutch, fluid gets added to the reservoir but only in the amount that is lost. It maintains the reservoir level. It doesn't matter if you have 2 quarts in the bleeder tank, it will only add fluid to the reservoir in the amount that is lost in the bleeding process.

 

[Jlaa]

@Jlaa you are wrong here. Used properly the Motive bleeder maintains the level in the cars reservoir at the exact level you started at. It will never add extra fluid to the reservoir if you bleed the pressure at the Motive tank first. That is the genius of the system. It maintains the level in the reservoir that you started with.

As you bleed at the clutch, fluid gets added to the reservoir but only in the amount that is lost. It maintains the reservoir level. It doesnt matter if you have 2 quarts in the bleeder tank, it will only add fluid to their reservoir in the amount that is lost in the bleeding process.

OH!!!!! NOW I UNDERSTAND!!!! THANK YOU!!! I was traumatized by our "doing it wrong process" and didn't realize this.

(Now lets talk what happens when you do it wrong and unscrew the red Motive reservoir cap while still pressurized. All the positive pressure in the bleeder tank forces all brake fluid in the hose into the reservoir causing a huge mess. That is why you relieve pressure in the bleeder tank first and the brake fluid in the clear hose flows in the other direction back into the bleeder tank.)

However, all the 124/210 reservoirs have dual chambers, to ensure a loss of fluid in either front or rear will not cause a loss of braking power in the other half. What you describe may be unique to Superbeetles? Its not an issue with 80s through 00s Mercedes.

Here is a diagram of the reservoir. It seems similar to what you describe? Anyways, it is possible, using the dry method, to bleed the clutch side dry if one is not careful to maintain a high enough fluid level in the reservoir to ensure fluid breeches the wall and spills over to the clutch side.

 

[gsxr]

Here is a diagram of the reservoir. It seems similar to what you describe? Anyways, it is possible, using the dry method, to bleed the clutch side dry if one is not careful to maintain a high enough fluid level in the reservoir to ensure fluid breeches the wall and spills over to the clutch side.

Yes! The MB reservoirs are similar, and you need to verify both sides are full. There's a metered channel of some sort between them which allows the 'hidden' reservoir to partly drain into the visible reservoir, when siphoning out dirty fluid. There's no way to fully extract dirty fluid from the hidden reservoir without removing it from the M/C, which is generally a Bad Idea unless removing the M/C or booster.

Note that when bleeding/flushing, when I fill the reservoir, I fill it all the way to the very top (nearly overflowing). This keeps both reservoir sections completely full. I use the bleed process described above to have an end result at the MAX level.

 

[RicardoD]

The trauma is REAL Jlaa!

 

[500AMM]

@Jlaa if you manage to put a tiny U-shaped pipe over that wall inside the reservoir, the level will even out during bleeding. Maybe a challenge to get the pipe in there - if possible at all, and fish it out again, but it should work.

 

[Jlaa]

@Jlaa if you manage to put a tiny U-shaped pipe over that wall inside the reservoir, the level will even out during bleeding. Maybe a challenge to get the pipe in there - if possible at all, and fish it out again, but it should work.

[ATTACH alt=fluid level equalize.jpg]161287[/ATTACH]

Ah! There is a 100% probability that, if I were able to use such a pipe and get it in there, over the wall, that I would lose it and it will get stuck in there, forever lodged there ...... blocking something thus necessitating me having to replace the entire reservoir!

 

[Jlaa]

@Jlaa having bled my clutch today (on my 964) after our lessons learned from yesterday, at 25psi of pressure in the bleeder, it was very easy to unscrew the large cap on the bleeder. It is not that bad to pump up to 25psi. Just keep it simple (but knowing you, you will create the ultimate Motive Bleeder mod, and I will await the parts list when you have this all figured out).

EDIT: I think these two 1/4 NPT bits will work to get the setup you want Jlaa. Just put them behind the pressure gauge on the Motive bleeder. Then you need a battery powered pressure pump to slowly raise the pressure in the Motive bleeder. I wouldnt hook up 110 psi shop air and blow up the system.

View attachment 161129

T- fitting.



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@RicardoD thank you for the inspiration. I used two 1/8” NPT Tee fittings to add a schrader valve (no manual pumping needed!) and a knurled knob pressure release valve. Now I have the laziest-ever-man’s hotrod pressure bleeder.

 

[RicardoD]

I love the pressure release valve. A big reminder to release the pressure there. Can't wait to copy your setup and bleed the brakes on my E500. Haven't done it since 2018 when I changed to stainless steel brake lines. Also curious to see what the new brake fluid moisture tester indicates. General guidance on fluid change is 2 years or 20k miles.