Replaced brake components and started to pressure bleed right front. NO brake fluid, any ideas?

[Witt1962]

Hello guys,
This is really something. I replaced rotors, the flexible brake lines, rebuilt the calipers. Nice, Porterfield pads on Zimmerman rotors. I went to bleed the right front and no brake fluid at bleeder even under 15 psi. From the Motive pressure unit. I removed the new Deerfield brake line, it's dry. I drove the car and all is well, except no right front brake.
ABS hydraulic unit?
Is there a check valve or blocking solenoid?

Has anyone ran into this problem? The car is parked again.
Any ideas would be appreciated.
David

 

[jgt157]

What condition are your flexible brake lines? It could be rusted inside...

 

[Klink]

Hello guys,
This is really something. I replaced rotors, the flexible brake lines, rebuilt the calipers. Nice, Porterfield pads on Zimmerman rotors. I went to bleed the right front and no brake fluid at bleeder even under 15 psi. From the Motive pressure unit. I removed the new Deerfield brake line, it's dry. I drove the car and all is well, except no right front brake.
ABS hydraulic unit?
Is there a check valve or blocking solenoid?

Has anyone ran into this problem? The car is parked again.
Any ideas would be appreciated.
David

Likely a plugged ABS hydraulic unit. Sometimes you can unplug them by removing the metal line between the unit and the master cylinder marked "V", then blowing compressed air through the unit in the reverse direction.

 

[Witt1962]

What condition are your flexible brake lines? It could be rusted inside...

Jgt157,
thank you. All of the old fluid that came out of the calipers and lines was nice clean looking blue, and appeared to be the old Ate blue fluid. I should have noticed something was up when a good volume of fluid came out of three calipers but not the right front during the rebuild. I don't have a ABS light illuminated, so I would think that this car would have a fail safe fluid bypass to the caliper. Not sure what's up with this and now I'm on line looking for a solution.
Thanks again ANY idea is welcome.
Cheers
david

 

[Witt1962]

Likely a plugged ABS hydraulic unit. Sometimes you can unplug them by removing the metal line between the unit and the master cylinder marked "V", then blowing compressed air through the unit in the reverse direction.

Klink,
i believe your on the right track. I will head back out to the garage and see if I can identify the "V" line.
Thank you,
david

 

[Klink]

Klink,
i believe your on the right track. I will head back out to the garage and see if I can identify the "V" line.
Thank you,
david

I should have mentioned, any markings that you see on the master cylinder or the hydraulic unit will have the letters H, V, L, and R.

H is rear. V is front. L and R are left and right, same as in English

 

[gsxr]

Bump the pressure to 30psi as well... 15psi may not be adequate.

 

[Witt1962]

Klink, GSXR.
Thank you.
I will put the car back up on stands today. I soaked all of the ABS hydraulic unit fittings yesterday. I will move up the pressure to 30 psi and remove some lines and use the air compressor. Thanks again guys, I will run more fluid through all the brake lines.
david

 

[Witt1962]

Well, I was unable to make any progress with pressurized brake fluid or air pressure. The hydraulic ABS unit works great in all channels except Right front.
Does anyone know if this is a junk yard only item?
I am sure this is a high dollar item for a 2K car.

I know it would be a sin to some and could I just bypass the ABS unit and just run the lines from the master cylinder and put an adjustable brake proportioning valve on the rears. Or will the car even start without the ABS active?
and yes I know all about how safe Anti lock brakes are on cars.

ALL IDEAS ARE WELCOME.
Cheers.
Witch

 

[modzona]

No problem to start and drive the car without the ABS connected. You just will get ABS warning light on.

 

[Klink]

You can junkyard those all day long.

 

[Witt1962]

Modzona,
Thank you for the prompt reply. My biggest concern with elimination of the ABS is the electrical repercussions.
Best Regards,
David

 

[Witt1962]

Klink,
thank you for the prompt reply. Is this Bosch ABS common to lots of cars or is this E420 specific?
cheers,
David

 

[Klink]

Klink,
thank you for the prompt reply. Is this Bosch ABS common to lots of cars or is this E420 specific?
cheers,
David

I will look it up as soon as I'm close to a computer, but I'm pretty sure that just about any 124 with ABS will use that same hydraulic unit.

 

[gsxr]

ABS units are a rare failure, so they are plentiful and cheap in junkyards or eBay. Since your car is non-ASR, I believe most all years of 124 can be a donor, although I'd generally prefer a late (92-95) donor with lower miles, if possible.

DO NOT try to bypass the ABS unit. More headache than it's worth.

 

[Klink]

Almost all of those 3 channel ABS hydraulic units from about '86 on are the same. It is in millions of MBs world wide. Make sure that it has the same "sloped top" plastic cover like yours, and it will be the same unit. There is an earlier version, like '85 -ish and prior that has a flat plastic cover on top. Even though it may work, don't get one of those.

If you look by MB part number 001 431 80 12 is the current number. Obviously if you match the Bosch number on your installed unit, you will be good to go too.

 

[Witt1962]

OK Gentlemen,
Remove and Replace it will be. Klink and GSXR, THANK YOU again. Unfortunately, I am shopping around the Miami area where everything is a little fishy. I may see if a member has one on a junk car.
All the Best,
David

 

[Witt1962]

This story has a happy ending. Went to EBay found a number matching ABS hydraulic unit. 80.00. Free shipping and arrived promptly. No stripped fittings, clean and just plugged in to my car. I ran about a quart of fluid through the new unit and lines.

Car now stops great.
Thanks for all the great support.
David

 

[gerryvz]

Thanks for the update !!

 

[samiam44]

I only get a little out of the right front. But it does bleed, but there is a restrictio. Asr car.

M