Brake issue - Booster, Master Cyl or ?? Can't lock wheels up
 

I just recently replaced my brake pads and rotors, bled the system as it should have been. I was trying to get rid of a problem wherein I CANNOT lock the wheels up. I don't have ABS.

I can be going 60 and put both feet on the pedal and it will haul down in decent time, but the wheels never stop turning.

These are 5 year old michelin xgt v4's so they aren't the newest stickiest rubber.

Also, the pedal takes more effort to haul the car down than does our 97 GLE. It has ABS so I haven't assessed the ability to lock them up obviously. Without the GLE ABS kicking in, the GLE can stop probably stop in 1/4 less distance than the SE.

No brake fluid loss anywhere. In short the car just does not stop as quickly or as confidently as I feel it should (or by comparison to our GLE).

Since pads, rotors and a bleed have been done, I'm thinking of either pointing a finger at the master cylinder or brake booster.

Thoughts or advice? thanks for reading.

so is the carin question an 97 SE ???
and are you sure it doesnt have ABS??

Yup the 97 SE. 109k on it. GLE has 129k and has ABS.

The SE does not have ABS. It just does not stop confidently like the GLE does. In other words the GLE stops shorter and with less pedal effort by far than the SE with new(er) rotors, pads and brake system bled.

The GLE is going on 4 year old pads, rotors that need to be replaced and a system that has NEVER been bled.

could it be a case of bad rubber lines maybe?
did you bed in the brakes properly?
also could be the booster...i just read the op and saw that you haveto put two feet on it .
dont mean to answer your question with questions just trying to get the whole picture.

Yes I did about 5 40-5 stops and about 5 60-5 stops with cooling time in between. I don't have to use 2 feet to stop, but even if I do that I cannot stop as quickly as the GLE by any means.

You mention bad rubber, if they aren't leaking is there something else about them I should look for?

Definitely change those tires, that should help. I just changed mine and I can tell the difference between before and now. Don't know what else to tell you. :(

sounds like you need struts.
struts help to control weight transfer and when functioning properly they keep braking distances down. worn struts can easily increase stopping distances by 25%

9 month old tokico blues plus all rubber bits... FSTB and RSB. Handles like its on rails. The GLE on the other hand.... original shot struts.

On the tires, I'm planning on getting some new michelin pilot sport a/s in the next month or so, but the problem is the lack of confidence in being able to make quick stops. If they were old/hard I think they'd break loose before they are supposed to?

what was braking like before the new parts? if the problem started after the new parts were put on, i would wonder about parts quality, cleaness of rotor surface and caliper condition. check all. did you clean the rotors with a brake cleaner spray? did you have a hard time pushing/turning any piston back into the caliper? did you free up & lube all of the caliper pins?

hows the brake pedal feel in SE vs. GLE? is the SE's pedal softer than GLE? is there more play than the GLE's? have you checked the brake booster hose for signs of cracks or other problems? Is your master cylinder leaking or show any other signs of malfunction? It might be the brake pads just don't bite as hard. What kind of pads did you put on? did it act the same way before you did the brakes or was it better/worse?

sorry man, had to leave for a while
anyway, after time the rubber can get soft so that when you apply pressure the brake lines give, or swell... instead of using the hydrolic force for pushing the pistons ,some of the energy is wasted in the faulty lines.

Braking overall was the same with the old parts vs. the new ones. I was disappointed to say the least.

Old pads were raybestos quietstop ceramic, new ones actually tried two kinds, bendix titanium metallic and wagner thermoquiet ceramic.

Brake cleaner used on all rotors, in fact over a period of a year I've warrantied all 4 calipers for new ones from advance to work that variable out. The two front pistons were of normal resistance to push back in, the two rears turned in with some resistance but were still 'ok'. Yes, silglide used on all caliper pins and new rubber boots used on them.

GLE brake pedal feels MUCH better when braking, more solid. During what I would call a quick stop, the pedal for the GLE does NOT go down nearly as far as the SE (problem child). No fluid loss, a quick check of the booster as per the manual shows nothing that really stands out. The pads before (problem still existed) were Raybestos quietstop, new ones tried were wagner thermoquiet and bendix titanium metallic. bedded in correctly, bled in correct sequence.

I have not checked the booster hose, which I will tomorrow.

I have a 1996 maxima and the right tire locks up (in snow and/or cold) - anyone know why?

caliper piston not good maybe

While braking, or after sitting overnight? With the ebrake on or off?

Post in the newbie thread, no reason to bump 4 month old threads.

Well I finally found out a bit ago what the braking problem was. The PS line was leaking where the soft rubber would connect to the loop in front of the radiator/condenser. It would then drip down/block back and eventually hit the hub/brake disc, pads etc. Finally traced it back and the inside of the tire was simply black with grease, the inside wall of the tire, the wheel well and everything else.

Replaced the hoses, connectors and spent about 2 hrs with degreaser. All was well, stops like it did before the leak, which I had not connected to the mess on the wheel or the weak braking on the that side.

Sorry I forgot to update.