Over the weekend I installed a new master cylinder and rear wheel cylinders on my 87 Dakota, trying to remedy a slowly sinking pedal while applying light to moderate pressure, like at a stop light. There was no loss of fluid, so I figured it was the MC. It was time to replace the shoes, so I did it …

I just re read your initial post. Did you bleed all four brakes? How did the front ones do? That slow sinking pedal could point to a partially collapsed rubber hose, or a slightly sticking caliper. On some cars, you can also get an air pocket above the front bleeder screw-sometimes have to remove t…

I am beginning to think that the leaking filler caps on the MC rez and the sinking brake pedal might be two different and unrelated problems. The MC and rear wheel cylinders are new. The lines have been bled. I have excellent braking. The pedal is solid upon braking and then it slowly starts to sink…

Thanks, Oldcars, yes I bled all four brakes, RR, LR, RF, LF, for the MC installation. The next day after rear wheel cylinders installation I bled RR and LR, did not bleed RF and LF as I did not open those lines since bleeding them the day before. I replaced the rear wheel cylinders after replacing t…

Just remembered running across this yesterday: "Does your 4Runner have rear drum brakes instead of discs? If so, worn or out of adjustment rear brake shoes can cause a low pedal and even mimic a failing master cylinder." Low brake pedal after new pads and bleeding? I just installed the brake shoe…

Adjusting the rear brakes may be all that’s needed.

The lids on those MC rez’s have to have a little hole in them to the outside air for it to work. Otherwise a vacuum or pressure area might form above the brake fluid and prevent the brakes from working. So it is possible during forceful braking for brake fluid to splash & squirt out that air hole i…

I adjusted the rear brakes until there was a very slight drag . The brake pedal engages the brakes at a higher position, but the sinking pedal persists. One puzzling thing is that the sinking is not consistent. Sometimes it does not occur at all, and when it does, which is most of the time, the onse…

Jack_Dak87: For the time being I am going to live with it That thought is not fair to the people who have to share the road with you. You have a problem with your brakes and you need to have a real brake shop solve it before you injure yourself or someone.

We’ve followed this guy’s discussions over the years, and Jack strikes me as a guy who is persistent and eventually solves his truck’s problems on his own

Leak from rear of new master cylnder

Maintenance/Repairs

Jack-Dak87 February 28, 2017, 10:19pm 27

Thanks, RK. I will give it a shot and report back

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Leak from rear of new master cylnder

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