Brake issues after wheeling

[Jeepoftheseus]

Hey folks,

So I drove up to Payson and Heber this weekend to offroad the jeep for the first time. It was a ton of fun. That being said, when I got to the end of a trail this morning before coming back home, I found that the brakes were no longer working right. It made getting home a little scary.

My peddle now goes all the way to the floor and I can even hear a bit of a wooshing noise sometimes when I'm on a level surface. The brakes will still bring the jeep to a stop but it's slow. After driving that way for a while, I pulled over at a gas station and pumped the brake a few times and found that it temporarily became firm again. That 'fix' didn't hold for even 10 minutes and now it doesn't seem to be replicable.

Curiously, on inclines and declines the brakes seem still to be somewhat firm and tight?! Lucky for me the trip from Payson to Phoenix is mostly down hill.

Also, the day before I left Phoenix I had the brakes flushed and bled at a mechanic. There wasn't an issue, I've just been replacing all the fluids because the jeep is new to me and I want to be able to accurately track them. I'm hesitant to blame the mechanic because the brakes worked fine for two days after, and the issue didn't occur until I was done with a pretty bumpy trail where I nearly got bucked out of my seat once or twice

I once did a complete brake job on an old 82' gold wing motorcycle but I've mostly forgotten how to work on them. The motorcyle didnt have a vacuum booster either. I also remember finding it really tedious (thus I had a Mechanic flush the brake fluid for me this time).

Any help pointing me in the right direction is appreciated as always

 

[CharlesHS]

Did you check the brake fluid level in the brake master cylinder ?
Have you gone underneath the Jeep and inspected the brake lines and each brake cylinder ?
Look at where the brake pedal is located and inspect for brake fluid leakage where the master cylinder actuating rod penetrates the fire wall.
If there is signs of fluid; the master cylinder is leaking and needs to be replaced.
When idling the engine; is the engine RPMs higher than what you are accustomed to ?
If so... the vacuum booster could have a leak or the hose going from the intake manifold to the vacuum booster could have come loose.

 

[TJ Jim]

If the brake master cylinder is full I’d say it’s bad. I’ve seen them fail after bleeding.

 

[John Cooper]

Did you check the brake fluid level in the brake master cylinder ?
Have you gone underneath the Jeep and inspected the brake lines and each brake cylinder ?
Look at where the brake pedal is located and inspect for brake fluid leakage where the master cylinder actuating rod penetrates the fire wall.
If there is signs of fluid; the master cylinder is leaking and needs to be replaced.
When idling the engine; is the engine RPMs higher than what you are accustomed to ?
If so... the vacuum booster could have a leak or the hose going from the intake manifold to the vacuum booster could have come loose.

But that's like work!

Honestly after a 9-10 hour day dealing with humans, I find spending time working on my Jeep therapeutic!!!!!

 

[TheBoogieman]

Honestly after a 9-10 hour day dealing with humans, I find spending time working on my Jeep therapeutic!!!!!

That's why I drive for DoorDash now. I pick up food and drop it off at someone's door. If I'm lucky, I never have to deal with anyone. Humans and traffic annoy me.

 

[John Cooper]

That's why I drive for DoorDash now. I pick up food and drop it off at someone's door. If I'm lucky, I never have to deal with anyone. Humans and traffic annoy me.

And yes i deal with both segments 5 days a week!!!! And yes i hate both

 

[TJ Jim]

I like my dog more than people. Even his friends are great. Well……one is a real bitch. There is no traffic in north west Tennessee

 

[Jeepoftheseus]

Lots of great stuff here, thanks everybody especially @CharlesHS .

So it doesn't look like I've lost any brake fluid after the 2 hour trip back or overnight outside my house. The engine idles as expected, and I can pump the brake till it's firm, and feel the pressure release once I turn the engine on. Am I correct in thinking this points to a worn master break cylinder?

One other thing: my e-brake feels less firm too. I can pull it all the way back now.

 

[CharlesHS]

I would bleed each of the wheel cylinders before replacing the master cylinder to confirm the master cylinder is the problem.

 

[KennethS]

If so... the vacuum booster could have a leak or the hose going from the intake manifold to the vacuum booster could have come loose.

My experience has been loss of vacuum to the booster makes the pedal very hard to push.
On the other hand, when I had a failing booster the pedal would sink to the floor very easily.

One other thing: my e-brake feels less firm too. I can pull it all the way back now.

Hmm. That indicates an issue with the rear drums. Maybe first try manually tightening the star adjusters to see if that makes an improvement. If not, might be time to pull the rear wheels and inspect the hardware.

 

[DuckNut]

And yes i deal with both segments 5 days a week!!!! And yes i hate both

People made me hate people.

 

[MikeE024]

Hey folks,

So I drove up to Payson and Heber this weekend to offroad the jeep for the first time. It was a ton of fun. That being said, when I got to the end of a trail this morning before coming back home, I found that the brakes were no longer working right. It made getting home a little scary.

My peddle now goes all the way to the floor and I can even hear a bit of a wooshing noise sometimes when I'm on a level surface. The brakes will still bring the jeep to a stop but it's slow. After driving that way for a while, I pulled over at a gas station and pumped the brake a few times and found that it temporarily became firm again. That 'fix' didn't hold for even 10 minutes and now it doesn't seem to be replicable.

Curiously, on inclines and declines the brakes seem still to be somewhat firm and tight?! Lucky for me the trip from Payson to Phoenix is mostly down hill.

Also, the day before I left Phoenix I had the brakes flushed and bled at a mechanic. There wasn't an issue, I've just been replacing all the fluids because the jeep is new to me and I want to be able to accurately track them. I'm hesitant to blame the mechanic because the brakes worked fine for two days after, and the issue didn't occur until I was done with a pretty bumpy trail where I nearly got bucked out of my seat once or twice

I once did a complete brake job on an old 82' gold wing motorcycle but I've mostly forgotten how to work on them. The motorcyle didnt have a vacuum booster either. I also remember finding it really tedious (thus I had a Mechanic flush the brake fluid for me this time).

Any help pointing me in the right direction is appreciated as always

Fwiw

I had a scarcely appearing issue where the pedal would go to the floor when braking in incline situations in the rocks (not ideal). The brakes would eventually come back after I pumped the pedal. I bled my MC and brake lines but it didn’t fix the issue for me.

If you have cruise control, see if CC will engage and then see if the brake pedal will allow you to disengage. I had a hard pedal that wouldn’t turn off CC, and later CC wouldn’t even engage.

In normal driving, the booster helped enough that I didn’t realize it wasn’t working as good as it should. The CC issues were found through luck since I hardly ever use it.

I also noticed a more pronounced wooshing sound when I pressed the brake while the vehicle was off. A new booster solved my issues.

 

[Jeepoftheseus]

Thanks for your reply! It turned out that the rear brake pistons are broth pretty shot. I still haven't replaced them because it's so hot outside right now I don't want to do it lol

 

[MikeE024]

Thanks for your reply! It turned out that the rear brake pistons are broth pretty shot. I still haven't replaced them because it's so hot outside right now I don't want to do it lol

What do you mean they are shot...is there a leak?

Also, the front brakes do the majority of the braking. If only stuck, I don't understand how that would cause your pedal to go to the floor.

I'd try to figure this out before its 10-20* hotter outside and before someone gets injured.

 

[Jeepoftheseus]

Yes, the rear pistons are leaking and accordingly I don't have braking pressure. No, of course I'm not driving it.

 

[MikeE024]

Yes, the rear pistons are leaking and accordingly I don't have braking pressure. No, of course I'm not driving it.

It's great you found the leak. Best of luck fixing it all up.