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There are different boosters for 1990's vintage MB's, both single and dual chamber. The dual-chamber provide additional pedal assist ("boost") vs single. There are various levels of boost. See chart at PDF page #6 at this link, the "boost factor" shows the relative difference.
Boost factor only affects pedal effort, which is NOT the same as braking power. Too much assist means the pedal is very sensitive / touchy, which is annoying. Too little assist and the pedal requires a lot of force / leg muscle to get the stopping power you want. To get more braking power (reduced stopping distances) you need larger brake rotors/calipers, and/or different pad compound, and/or stickier tires.
Click the link below for my journey down the booster swap road from almost 15 years ago. Read the whole thread, it starts out all sunshine and lollipops, but storm clouds appear in post #2:
TLDR: Pedal feel is highly subjective, and what one person thinks is great, another may not like at all. Pad compound can seriously affect pedal feel as well. Bigger is not always better, as I learned the hard way; I had to "downgrade" to a different setup after my big MC+booster turned out to be un-modulateable (hmmm, is that even a word?) during trail braking.
E-Class (W124) - W124 brake booster & master cylinder upgrade - Hi everyone, As you may (or may not) recall, I installed early 500E brakes on my 1987 300D earlier this year (300mm front (http://www.w124performance.com/images/W124_brakes/300mm_front2.jpg), 278mm rear...
There are different boosters for 1990's vintage MB's, both single and dual chamber. The dual-chamber provide additional pedal assist ("boost") vs single. There are various levels of boost. See chart at PDF page #6 at this link, the "boost factor" shows the relative difference.
Boost factor only affects pedal effort, which is NOT the same as braking power. Too much assist means the pedal is very sensitive / touchy, which is annoying. Too little assist and the pedal requires a lot of force / leg muscle to get the stopping power you want. To get more braking power (reduced stopping distances) you need larger brake rotors/calipers, and/or different pad compound, and/or stickier tires.
Click the link below for my journey down the booster swap road from almost 15 years ago. Read the whole thread, it starts out all sunshine and lollipops, but storm clouds appear in post #2:
TLDR: Pedal feel is highly subjective, and what one person thinks is great, another may not like at all. Pad compound can seriously affect pedal feel as well. Bigger is not always better, as I learned the hard way; I had to "downgrade" to a different setup after my big MC+booster turned out to be un-modulateable (hmmm, is that even a word?) during trail braking.
E-Class (W124) - W124 brake booster & master cylinder upgrade - Hi everyone, As you may (or may not) recall, I installed early 500E brakes on my 1987 300D earlier this year (300mm front (http://www.w124performance.com/images/W124_brakes/300mm_front2.jpg), 278mm rear...
Thanks @gsxr
really appreciate the information. That is exactly what i have concluded. However there are write ups that state dual diaphram boosters provide more brake fluid pressure to disc brakes. especially big brake upgrades.
Power brake boosters offer lower pedal effort and better braking characteristics, but which one is right for your hot rod, muscle car, or truck? We take the guesswork out of that question with our latest buyer's guide.
Thanks @gsxr
really appreciate the information. That is exactly what i have concluded. However there are write ups that state dual diaphram boosters provide more brake fluid pressure to disc brakes. especially big brake upgrades.
More pressure isn't always a good thing. As noted in my previous post, too much pressure (for a given amount of pedal effort) results in a super-touchy pedal that is basically unusable for normal driving. You only want/need a larger booster, with more assist, if you find it requires too much pedal pressure for the desired braking power. If it feels like there's no power assist, yeah, you may need a bigger booster.
"Single diaphragm brake boosters are commonly used for four-wheel drum or front disc/rear drum brake system configurations. Since drum brakes require a lower fluid pressure to actuate, the single diaphragm provides enough assistance. When upgrading to four-wheel disc brakes a dual diaphragm brake booster is recommended due to the higher fluid pressures required to move the multiple disc brake caliper pistons found at all four corners of the vehicle."
All modern MB's have 4-wheel discs and few of those have a single-diaphragm booster.
There are different boosters for 1990's vintage MB's, both single and dual chamber. The dual-chamber provide additional pedal assist ("boost") vs single. There are various levels of boost. See chart at PDF page #6 at this link, the "boost factor" shows the relative difference.
Boost factor only affects pedal effort, which is NOT the same as braking power. Too much assist means the pedal is very sensitive / touchy, which is annoying. Too little assist and the pedal requires a lot of force / leg muscle to get the stopping power you want. To get more braking power (reduced stopping distances) you need larger brake rotors/calipers, and/or different pad compound, and/or stickier tires.
Click the link below for my journey down the booster swap road from almost 15 years ago. Read the whole thread, it starts out all sunshine and lollipops, but storm clouds appear in post #2:
TLDR: Pedal feel is highly subjective, and what one person thinks is great, another may not like at all. Pad compound can seriously affect pedal feel as well. Bigger is not always better, as I learned the hard way; I had to "downgrade" to a different setup after my big MC+booster turned out to be un-modulateable (hmmm, is that even a word?) during trail braking.
E-Class (W124) - W124 brake booster & master cylinder upgrade - Hi everyone, As you may (or may not) recall, I installed early 500E brakes on my 1987 300D earlier this year (300mm front (http://www.w124performance.com/images/W124_brakes/300mm_front2.jpg), 278mm rear...
watching with popcorn, but curious if there is an E500E definitive fix for the noisey result from stepping on the brake pedal? (audible annoyance only not a braking problem)
Got it. You upgraded 2 steps, from the single-diaphragm 10" with 3.85 boost factor used on most 6-cyl 124 and most W202, to the dual-diaphragm 8/9" with 5.60 boost, used on the 400E/500E and most R129's to 1997. Should be a pretty big difference.
Got it. You upgraded 2 steps, from the single-diaphragm 10" with 3.85 boost factor used on most 6-cyl 124 and most W202, to the dual-diaphragm 8/9" with 5.60 boost, used on the 400E/500E and most R129's to 1997. Should be a pretty big difference.
Yes. i retained the stock C36 master cylinder. not sure what the difference of master cylinders. physically, they looked very similar so my mechanic just decided to keep the stock one.
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