Rmoving GQ Rear Brake Rotor

[aflman]

Hi all, I'm new to this forum and hope someone can please guide me on how to remove rear brake rotor from my efi GQ Patrol. Once I remove the caliper I notice there are two small guide holes on the sides and a larger hole at the bottom as in my picture. Thought this larger bottom hole might have a hex shaped nut that needs to be removed but not the case. The inside of the rotor has been damaged by pad and want to get off but not sure how. If anyone can please assist me that would be great thanks.

[Silver]

First of all, the handbrake is seperate and on the transmission? I've never heard of a handbrake inside the rear discs on a GQ, but you never know what someone has changed :-)

I don't think there is anything that holds them on to the wheel studs and the hub except the crud and rust that builds up around the wheel studs.

It may be that the small holes are threaded, to take a bolt, maybe M8 x1.25 or something - if so you can thread a bolt in either side and use that to ease the rotor off.

Otherwise thoughtful use of a hammer might be called for. Keep it coming straight along the wheel studs, or you'll damage the thread. Start of lightly, and evenly around the rotor, and see how you go.

[gec]

First of all, I hope you have a jack stand under there and you are not just working on it with just the jack, second, did you put the caliper back on for the pic or is there really no brake pads on there, and third if you pull the caliper of you should be able to pull the disc of to replace it, If its a bit stuck some gentle tapping around the edges to loosen things up will do wonder's, Cheers.

[aflman]

Thanks heaps guys. I have a stand on the other side of the axle and put the wheel under the rear door chasis too :) I'm certainly old enough and not as dumb as i used to be to know not to put myself anywhere under the Patrol. Caliper slides upwards once I undid the bottom bolt (only one you can undo). I took the pads off and once the rear pad came off I realized the pad had worn into the disc and there is too much damage to machine it. Couldn't tell before I took rear pad off as there is a guard there covering disc. So, want to replace rotor and pads. The other rear rotor is fine but never have taken a rotor off before, only replaced pads.

So, if I take the 3 bolts off from the back of the caliper (one bolt holds hose in place), then rotor should come off? That larger hole on the bottom does nothing? Thanks Silver, the smaller holes are threaded. Is it OK to replace just the one rear rotor if the other one is fine? The rubber boot around the piston is also torn on one side.

[gec]

Cool, just checking, cause ya cant see the stand in the pic, If ya unbolt the caliper the disc will come off, but I would be replacing both discs and pads, when you do it check the slides on your calipers to make sure they haven't seized, this may be what is causing one side to wear more than the other, It may pay to pull them off and put a kit through them if that is the case, Its pretty easy to do.

[aflman]

Thanks gec. I will do both, it's stretching the budget but the right thing to do. I got Bendix pads this time instead off genuine nissan pads.

Should I get a new rubber sleeve/boot for the piston? Is it easy to replace this? So, you can get a kit for them. Thanks again and Cheers

[mudmav]

i would also like to know how hard it is to put a kit in them , suspect i have a leak , the outer rubber seal is fairly knackerd and there was oil built up throught ive cleaned it up to see if it was axle or brake seal but nothing leaks at the moment and i dont know the history of this 89 mavpatrol apart from owner was pulling bits off it and replacing them with bits off his .where is the cheapest place to get the seals if im not pushing it too far, as for afl man years ago i tried to do the same thing on a set of drum brakes but could not get the blasted outer off , tried and tried bashed vit prised it broke screwdrivers broke small peices off the drum then someone said to me hey you got the handbrake on youll never get that off if youve got the handbrake on sure enough problem solved and two hours of blood sweat and profanities later.

[aflman]

Hey mudmav like that one lol. Reckon we all have stories like that. Good thing is we usually get there in the end and learning is what makes it worthwhile and the fact that I'm getting a kick out of being more of a handyman these days. Wanted to learn more when I was younger but spent most of my spare time chasing the fairer sex and getting over hangovers!!

[gec]

Here is a basic rundown on what to do. Most auto parts stores will be able to get a kit for you.

http://www.ehow.com/how_6759258_fix-sticking-brake-calipers.html

[Silver]

if the caliper completely clears the rotor with only one bolt undone, then that should do it.

While the holes are there for the bolts to ease the rotor off, given you are going to replace the rotor, and as the threads are likely to be a bit rusty etc, I'd just stick with lightish taps of a mallet, ideally, or a hammer (wear eye protection in case of chips). Keep them even around the circumference of the rotor.

Brakes are a key safety system - I'd suggest you only work on them if you are equipped with the manual and/or have the relevant experience yourself or access to someone who does. Replacing pads and rotors is perhaps not in the same league as rebuilding a caliper, but as Clint Eastwood once said, "A man's gotta know his limitations'.

You can buy exchange or new calipers, by the way.

I think it is best practice to replace brake components at both ends of the axle at the same time. don't ask me for a rational reason why - except that if one side has failed, it is likely that the other side soon will :-)

That rubber boot keeps the shaft clean and lubricated that the caliper slides in and out on. If it is damaged, that could be the reason why the inside of the rotor is also damaged. The slight wobble in the rotor was insufficient to push the pad back out of contact.

What you need to know is that rubber components that are part of the braking system, being designed for use with brake fluid, are incompatible with ordinary petroleum based lubricants, and solvents. So the right solvent is needed to clean things up, and rubber grease or brake fluid is used to reassemble.

Best practice would be to replace that split boot. I could not obtain one for Silver, and as a stop gap measure, I glued it back together with super glue. So far so good, but I need to track down new replacements. As the pad wears, the boot will extend, and doubtless the repair will fail.

In summary, if you know how to do all this, then sorry, and carry on. If it is all new to you, given it is brakes we are talking about, consider getting expert guidance - particularly once you are past the stage of replacing pads and maybe the rotors. My opinion, anyway :-)

[aflman]

Thanks again guys for all your great advice. Cheers