Question about my brakes :?:

twingopower · Posted: Wed Jan 03, 2007 9:37 pm Post subject: Question about my brakes :?:

Hi everyone,

I have recently registered and am new to the diff-lock forum and I was hoping some of you might be able to help me with my issue on my R Reg Cherokee 2.5TD Sport.

I am finding that as soon as the roads turn wet I am locking up my wheels very quickly, especially the front wheels. It could best be described as the brakes working with an on or of position and there does not seem to be a lot of feeling to the brakes, i.e. where one can feather the brakes and or progressively brake harder. An other way to describe this is all or nothing really. So far I have not crashed but it does not inspire confidence, especially to my partner.

So since trying to solve this mystery I have taken the car to a garage, a place on par with kwick fit for a quick check up to see if anything was wrong and nothing was found. The calipers were free to move, the pads had enough on them and the disks were OK, though the inner sides had a little more rust but nothing too severe and I think this would just reduce the effectiveness of the brakes, not cause the effect of locking up with minimal braking effort.

Next thought is the Tyre's maybe, well they have enough thread on them (had that checked too) and they are 4 x Goodyears Eagle GA 225/70R/15. Anyone ever experience issues with rubber going hard with the colder temperatures and therefore a significant reduction in road holding especially when breaking? If I were to replace them what would be the best replacements for them, I do occasionally go to a 4x4 track and play about in the mud and these currently seem to clog up very quickly.

I have talked to the main dealer about this issue too and all they could tell me that for some people they had reduced the sizes of the rear cylinders as people found the back would lock up too soon, well that does not seem to be my issue. So no answer there really.

So has anyone from the forum heard of a similar issue or know a solution? I am not that keen on changing out parts just like that to try and solve my issue if I am not sure what is causing the problem.

Well many thanks in advance and hi to everyone,

Regards,

Bernard

daggie · Posted: Thu Jan 04, 2007 8:31 am Post subject:

welcome

ours grabs first thing in the morning, thats it

fattyfattyboomalatty · Posted: Thu Jan 04, 2007 7:30 pm Post subject:

My rear brakes grab first thing in the morning but tends to only be the rear.

chancer · Posted: Fri Jan 05, 2007 8:39 am Post subject:

This isn't a problem that normally afflicts jeeps - quite the opposite in fact. They're not normally known for their strong braking.

The back wheels tend to grab more as the brake pads and drums get towards the end of their life, but leaky rear cylinders (and associated poor braking) is also typical.

Sometimes a front piston might lock on first thing in the morning if the caliper assembly has got a small dod of rust in the piston housing, but that normally clears as things warm up.

But neither of these scenarios fits your problem, so forgive me for rambling.

I would suspect that it might be something to do with the brake booster having too much vacuum in it, for some inexplicable reason, or something in the master cylinder not allowing the pressure to back off sufficiently to return to "normal". Can we assume that the car rolls perfectly fine and that the brakes aren't dragging at all?

Cartman · Posted: Fri Jan 05, 2007 3:54 pm Post subject:

1st thing in the morning if it has been damp overnight the non-Jeep front disks corrode and grab very badly. Bit a few dabs of the brakes clears that.

Tyres. Well we had the Goodyear eagles on ours when we bought it and both rears had only 3k on them and their wet weather ability was pants to be honest. Changed for a set of BFG AT/KO and have never looked back Very Happy

twingopower · Posted: Sat Jan 06, 2007 12:28 pm Post subject:

Thanks for the replies, I am thinking it might have been some surface rust on the disks as it had been standing for a while, making them very grabby. Since then things have improved a little as I have been driving the car on a daily basis, though I am tempted to try and fit new tyres as mentioned by cartman.

On that matter of tyres, I currently have 225/70R/15 and was thinking of going for 235/75R/15 as recommended by the jeepclub.co.uk site. Does anyone have any experience by doing so, or should I stick with the sizes I have at the moment?

Thanks again for you help,

Bernard

woody · Gate Opener Joined: 29 Mar 2005 Odometer: 30

Bernard

I run 235/75R15 BFG ATs on my XJ and have been chuffed with them. I feel they give better grip onroad than the Good Year Road Tyres originally on there. Have not really noticed any other problems.

Woody

daggie · Posted: Sun Jan 07, 2007 8:33 am Post subject:

you can't go wrong with BFG at Cool

mrstu · Posted: Wed Jan 10, 2007 1:17 pm Post subject:

The GY Eagle GA are shocking! I don't know why Jeep ever put them on as standard. BFG AT are loads better on road and off.

On the topic of locking up the fronts too easily check that the rear brakes are working as effectively as they should. If they're not good the fronts have to take the extra load and can lock up. Check the rear linings and adjust them correctly - the self adjusters are pants.

Hope it helps,

Stu.

bigjeepman · Posted: Wed Jan 10, 2007 2:04 pm Post subject:

Do the 235 75 AT's BFG fit on standard rims?

I think they should do

woody · Gate Opener Joined: 29 Mar 2005 Odometer: 30

Yep the 235/75R15s fit on the standard rims.

Woody