Dodge Repair/'99 minivan: Brake pedal soft/not holding
QUESTION: 1999 Dodge Grand Caravan 3.3L 4speed
When I stop at a red light with transmission still in D, everything is alright but then I feel the car is moving and I need to press more on the brake pedal to stop the motion (or sometimes I need to pump the brake pedal). I believe there is a problem in brake system but do not know what to check.
ANSWER: Hi Shafique,
Start by checking the that the brake fluid level in each of the two reservoirs at the master cylinder is full. Let me know if either one has apparently lost fluid since the last time you checked them. Notice also whether there is any signs of leaking fluid on the inside surface of the sidewalls of all four tires (streaking of dried fluid).
Is the brake warning light on the instrument cluster illuminated?
Please read the PS (below) and respond to it.
[an error occurred while processing this directive]---------- FOLLOW-UP ----------
QUESTION: I believe there is only ONE reservoirs at the master cylinder (next to the throttle body). Am I missing the other reservoir? I see only one cap for checking fluid level!
The brake light is not illuminated.
ANSWER: You are correct, I didn't first check my manual. So check the level in the one reservoir to see if it is down and look for signs of leaking fluid as I described. Then with the engine running but not in gear try stepping on the brake pedal with moderated effort and hold it and keep holding to see if it drops gradually or whether the warning light comes on.
Thanks for the rating and nomination, Shafique. Feel free to do both again if you would be so kind.
---------- FOLLOW-UP ----------
QUESTION: There is no streaking on the sidewall of any tire.
Pressing the brake pedal, with engine running and transmission in P, the pedal did not drop gradually and the warning light did not come on. However, I was able to push the pedal almost to the floor.
This is different than when the transmission is in D, I do feel that the pedal gets softer (drops) after may be 20-30 seconds.
The level in the reservoir was below FULL but above ADD line. I added some but no difference before and after adding the oil.
How recently had you added fluid to "full" mark? Ideally there should be no loss of brake fluid. So you might want to look inside all four wheel hubs to see if you find any leaking wheel cylinders. Or you can check the level again in a few weeks and if it has gone down then you do have a leak somewhere and you could check the brake lines and look inside the wheels.
If there is no warning light coming on, then check the vacuum hose that connects the intake manifold to the power brake canister to be sure there is no vacuum leak at either end.
I assume that by "oil" you actually meant that you added brake fluid, correct?
Finally, if no leaks, no warning light, and you are still having that pedal sinking situation it might be that there is an internal link inside the master cylinder proper.
Thanks for the rating/nomination. You are welcome to do that again if you believe I warrant that.