I recently replaced the front brake pads and rotors, and everything has been fine for about 100 miles.
Yesterday though, the brakes gradually get less effective until it felt necessary to stop. The pressure was there and it didn’t feel spongy, it just wasn’t stopping. It didn’t seem to want to pull to the side either. There’s no apparent leaks.
After sitting a while, they seemed to start working again.
I did notice that I failed to account for how high the reservoir would get – actually, I didn’t even open it when I retracted the pistons. The reservoir is filled to the brim, but I don’t know if that causes problems.
I’m not sure what to do except remove the excess fluid, clean them up, and relubricate them.
Alternative explainations may be that your rubber brake lines may be blocked or your pistons may be stuck open or you managed to create a leak in your piston seals when you compressed them w/o opening the reservoir and you’re now “greasing” your brake pads with brake fluid…
Either way, lift the Jeep and confirm that everything’s clean and working.
A few other possibilities.
The master cylinder is failing and aged brake fluid.
The brake fluid is aged and failing. Aged brake fluid boils at a much lower temperature and can lead to fade. If that is the original fluid that could explain a failing master cylinder or the brake fade and should have been changed back in the late 90s.
Feel the wheels after a drive that didn’t involve much braking. If one or more is really hot, brakes are dragging for some reason. Brake surfaces heating up and not working like they should. If this is the problem pads and rotor surfaces should probably be inspected. Diy’er me uses some 220 grit sandpaper to apply a slight cross-hatch pattern to the pads and the rotor when I have to remove the pads, seems to help the break-in process. OP’s symptoms seem unlikely to be caused by brake fluid boiling, as that usually causes pedal to go down noticeably further than before, spongy pedal feeling, etc.
Fair enough comment. But folks posting here should be welcomed, & feel free to ask any car related question they want to ask. Not have to be concerned that their question is showing they don’t know everything there is to know about cars.
It’s dangerous too because it can make the rear wheels skid if the front begin to fade. The ABS should prevent anything seriously bad from happening though if that’s working.
Once I was driving on a divided highway with a grass median. I looked over to see a cloud of dust and a minivan almost sideways with its rear wheels off the road and the front end in the fast lane. A Jeep could tip over doing this.
Oh, I absolutely agree that there are no dumb questions. But the OP’s questions implied that they had no idea what on earth could have caused their problems and it seemed that they had not done any reading up on the subject of working on their brakes nor watch any YouTube Videos on the it either. Their inquiry was as if they had gone into it blindly and that type of attitude scares the bejesus out of me.
I always advise folks to watch several YouTube videos first to learn tips, tricks, and what not to do before taking on any task that they are unfamiliar with. I practice this myself, if for no other reason to refresh my memory and to learn new tricks…
Which is why I always ask folks who are doing any plumbing work that requires soldering, “Do you have white bread?”
Year I have used bread many times but not needed for new construction.
I’ll have to say my first brake job was in 1968 watching, maybe not helping my bil much. Since then I have done many of my own before the internet and sometimes with the help of a manual. Never had a problem. As they say, it’s not rocket science.
The OP is waiting to read your details on the subject, XJ brakes are not complicated. Asking on an automotive message board seems to qualify as research. The disappointment is that most replies are to perform a Google or Bing search.
I am not a plumber, but if I was asked that question I would say if you needed white bread you should repair\replace the valve causing the problem and not use the white bread cheat. Just like a mechanic should always try to remedy any potential problems he finds while doing repairs.
Tcmichnorth, you are right, you are not a plumber. White Bread is not a “Cheat” it is a “Trick.” In lieu of White Bread, they now make a product that cost a whole lot more than a loaf of White Bread and is nowhere near as delicious… It is a type of dissolvable gel tablet the supposedly will not clog your faucet screens.
I learned about the White Bread Trick in the early 1980s (Before All Gore invented it… LoL…). We had recently bought a new house. The previous owner had installed a large covered and screened deck on the back of the house. What we did not know was that he had also installed an extension to the outside spigot that was under the deck and he put the new spigot in a discrete location behind a bush that we did not know about.
It was a very cold winter day and I received a phone call from my young teen son after he came home from school. He said there was water running down the driveway and it was flowing all the way from around the back of the house and from under the deck. He said he shut the water off at the meter.
When I came home, I found that the spigot extension was made of PVC pipe and that it had burst when the water in the pipe froze. I cut the PVC and glued a cap on and that resolved the immediate issue.
But to really repair it, I decided to install a shut-off valve on the copper pipe that the original spigot had been installed on under the house, in the crawl space.
With the water shut off, I cut the copper and tried to solder the new valve on and it would not take. As much time as I took draining the plumbing, opening faucets in the house and using a wet/dry vac, I could not get all that water out and every little drop seemed to create steam that prevented me from soldering. One of my “older, retired” neighbors (I laugh because I’m now older than he was…) told me to ball up a piece of White Bread and stuff the ball into the pipe. The bread would keep any water or steam from preventing me soldering the valve to the pipe. He also explained that once the water was turned on, the water would dissolve the bread and it would be flushed out the pipe.
Well, miracles of miracles, with the White Bread balled in the pipe, the solder job was completed in under one-minute…
I still preach the “secret” of White Bread, as demonstrated by these postings and I always, always check YouTube for new, and innovated ways to repair any product. If I had not done so a long while back, I would still be using a Forked Chisel to remove ball-joints in lieu of a ball-joint puller…
And in your reply, you wrote that you would not use a “cheat;” without even understanding the question. That is the mentality that drove the OP to perform the brake job without knowing how in the first place…
Yeah you can’t solder a pipe fitting if there is any water in the line. There is always water if you cut into an existing line. Pushing a lump of bread into the pipe absorbs the water long enough to sweat the fitting. Then dissolves when the water is turned back on. My godfather was a plumber.