Brake oil pressure problem

My 97 TJ needs the brake pedal pumped before driving or I get squealing from rear brakes when backing out of the drive way. This happens when the cold weather sets in. This was a slight problem last winter and had it checked in the Spring. I got a new set of tires and had the rear brakes checked. I was told there was no problem (it was warm than). I told them to bleed the brakes anyway in case it was a moisture problem. In early Fall, when it was still warm, I had to make an emergency stop and the vehicle heaved forward and nose-dived. As soon as it got cold this Winter the pumping of the brakes became necessary everytime fefore driving. I have not loss any fluid and have not seen any problem on a visiual inspection - pinches or such. Sooo.... combination valve? master cylinder? rear brake problem? some central distributions reguloator problem? Thanks, Steve in Michigan

97 TJ Sport 6 Auto AC > 90,000 stock No off roading Mechanical ability limited to maintainance & minor repairs
Reply to
popeyeball
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Reply to
L.W.( ßill ) Hughes III

That is just plain wrong.

Noise means the brakes are 'on'.

I would also be checking the emergency brake cables thinking they are set too tight. The adjustment for the emergency brake is the rear wheel shoe adjustment star wheel. The cable only gets set when installed and if the rear shoes aren't set first, then the cables become the pivot point for the shoes which causes strange rear brake operation.

The other thing that comes to mind is maybe you are using the emergency brake during the winter? If so, the cables can/will freeze up which holds the brakes in the on position. Pumping the pedal might be enough to break them free or they might stay locked on until friction heat lets them loose or you burn them up.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Reply to
RoyJ

Exactly right. The condition is called flash rust.

Spdloader

Reply to
Spdloader

Thanks for all the info. I did not consider mentioning the emergency brake. I rarely use the emergency brake. When I do use the emergency brake and I forget to release it, the E B holds fine going forward but rolls without much resistance in reverse. Sounds like the E B needs to be adjusted at the very least. I'll take it back to Firestone since I don't have a warm place to put around (and I'm not proficient at shoes & drums). Flash rust, I wonder if they'll know that term - I'll probably get a funny look. Any other sugestions? Steve in Michigan

Reply to
popeyeball

Just a term that describes the overnight rusting that occurs when humidity outside is high, and your brakes are warm enough to draw condensation.

Spdloader

Reply to
Spdloader

Reply to
RoyJ

Oh yeah! Sounds like a loosing battle.

Spdloader

Reply to
Spdloader

Reply to
Lee Ayrton

What I mean is: the phenomenon occurs as the brakes cool down. They have to be hot or warm to start with in order for it to occur.

Spdloader

Reply to
Spdloader

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