Mercedes R107 brake master cylinder and brake fluid reservoir - everything your need to know

[@siamak1]

Incredible. Mike you are encyclopedia! Extremely informative. Thank you.

[@MikesMercsandothercars]

Thanks for your kind comment. I'll pass the comment on to my wife who thinks I spend far too much thinking about cars! Mike

[@siamak1]

@@MikesMercsandothercars 😂

[@michaelsliwinski8044]

interesting, informative and invaluable

[@MikesMercsandothercars]

Thanks! Mike

[@marcosortolani3639]

HI! I'm looking forward to seeing the video on how to adjust the TPS. Thanks!

[@MikesMercsandothercars]

Do you have a problem with your TPS? - If so, what make model and year car do you have? Mike

[@marcosortolani3639]

@@MikesMercsandothercars Hi Mike! Mecedes 1975 6 cylinder. TPS is 5 pin. My engine revs up when I step on the accelerator and makes bangs. My problem is with the TPS calibration. Thanks!

[@MikesMercsandothercars]

@@marcosortolani3639 Is it a R107? and is it D Jetronic? Are you referring to the throttle switch detailed at the link below: jetronic.org/en/d-jetronic/tps Mike

[@marcosortolani3639]

@@MikesMercsandothercars It's a W116 280SE with TPS 0280120015.

[@MJR67]

Many thanks. On my slc the prior owners decided in their wisdom not to change the grommets to the reservoir. If it were only a case of stripping the paint I’d have been a happy bunny. Brake fluid actually ate through the steel which proved to be a real pain in the posterior. The gasket to the booster was also shot. Lucky for me, it was rebuildable. But yes, pound foolish grommet and gasket are cheap vs rust repair.

[@MikesMercsandothercars]

Yes...I suppose if owners are not getting their cars serviced regularly, small leaks at the brake booster can get over looked.....and you we all know how quickly a small problem can become VERY expensive. Glad to hear you got yours sorted. Mike

[@Andrsme]

Super informative video, thank you. My master cylinder is leaking on the outside (not into the brake booster) and I plan to use some UV liquid to track it down exactly but before I do it: would you say its common for the grommets between the reservoir and master cylinder to leak?

[@MikesMercsandothercars]

Yes - it’s common for those grommets to leak. It should be relatively simple to ascertain whether it’s those grommets leaking or the cylinder itself. Tie some toilet paper round the grommets (eg between tank and cylinder) and drive the car and brake a few times. See if the toilet paper is wet. Mike

[@Andrsme]

@ thank you! I’ll do that soon. I have the car parked at my mom’s place so I can only work on it on weekends. Is there anywhere else it would leak from on that side of the brake booster? I saw some fluid tracing down from the cylinder and I’m thinking it’s either a grommet or a loose brake line but I want to make sure I’m not missing anything.

[@MikesMercsandothercars]

@@Andrsme Wipe everything down and then tie small bits of toilet paper round the brake line fittings...and the grommets. Mike

[@Andrsme]

@@MikesMercsandothercars thank you again for the guidance. Cheers!

[@martinowens5309]

Mike you have done it again! I had a brake light on my 1972 r107 and took the parking switch out and it is fine. Turns out it’s one of the floats in the reservoir is not floating. Do you know if you can replace or repair the float? Thanks 😀

[@MikesMercsandothercars]

Those floats get pin holes, fill up and then sink - the later reservoirs have a slightly different design to get round this. I’ve never tried repairing one….but I’ll have a look and see if I have a spare. Mike

[@5aldl]

How to address the dampness in the brake booster before its too far gone? Because It seems that there is a little seepage inside.

[@MikesMercsandothercars]

Are you saying you have brake fluid in your brake booster? When I take the brake master cylinder off my Pagoda, I will do a video on the subject...especially if the brake booster is wet/damp inside. Mike

[@5aldl]

@MikesMercsandothercars Sorry, I did not clear myself, I wanted to say that my 107 is currently having the same issue, and I wanted to know how to address it before installing the new master cylinder. Or if it is just a little seepage, I can install the new master cylinder and everything will be fine? And I wanted to add that I really appreciate the efforts put in your videos, and I'm lucky even this video is coinciding with what I'm facing currently 😂

[@MikesMercsandothercars]

@@5aldl Hello - yes when you install a new master cylinder, this should cure the small leak causing dampness at the brake booster. Once you have taken the off the brake booster try to check inside the brake booster to make sure there is not a small pool of brake fluid. Mike