Brakes

Harry Chickpea · #1 12/22/10, 08:45 PM

I had some money budgeted for a brake job on the van but then there was a tire problem.

Problem with the brakes is the front pads need to be replaced. I have not noticed anything that makes me think I have leaking cylinders, seized calipers, or any of the other ways brake places make money. Is replacing the pads and leaving the rotors as they are a big deal? I've never done anything like this before. Is it something I can buy the pads at advanced and install them myself?

(95 Astro)

agmantoo · #2 12/22/10, 09:01 PM

Changing brake pads is a DIY project. Unless the rotors are worn or warped there is no reason to change them. You will need the pads and brake fluid, possibly a little brake cleaner and grease for the caliper slides. You need to do some research on how to move the brake cylinders back to a starting position as they are now extended.

blufford · #3 12/23/10, 06:07 AM

Here is a video for a 94 AWD Astro

mightybooboo · #4 12/23/10, 08:20 AM

Depends.You will be better off with turned or fresh rotors if the old ones have any grooves in em,then again a few 100 miles and the new pads will wear into (small) grooves and be pretty durn good,not new spec great,but plenty good.

IMO.FWIW,Ive done and do both.

**Cabin Fever** · #5 12/23/10, 09:58 AM

I have always just swaped out the pads without ever having the rotors turned. The pads will eventually form to the little grooves in the rotor.

My only bit of advice is to sand the rust off of the sliding surfaces on the calipers and apply some brake grease to these surfaces before reassembling.

foxtrapper · #6 12/23/10, 10:08 AM

Unless the rotors are badly chewed up, don't worry about replacing them. You're on a tight budget, just replace the pads. Yes, you can do it yourself.

agmantoo · #7 12/23/10, 10:22 AM

I was not impressed with the above video of the brake pad replacement. Rather than push the old fluid back into to the master cylinder IMO it would have been better to open the drain on the back and wasted that fluid. Brake fluid has an affinity to moisture and that moisture is what corrodes the inside of the wheel cylinders. I would have flushed the master and wheel cylinders and lines with new fluid. Worst case, in the video the filler cap should have been opened on the master cylinder so that the fluid could have spilled out. Lubricating the caliper sides is essential which he did not do.

backwoodsman7 · #8 12/23/10, 12:10 PM

Mostly good advice so far; bottom line is, it's an easy DIY job. Just a couple notes:

1. Brake fluid should be changed every year, although no one does it that often, not even me..

As agmantoo said, it's hygroscopic, and you gotta get that water out of the system to avoid rust and a much bigger repair job.

2. The manufacturers have specs for how big a groove a rotor can have before it needs to be turned or replaced. If anyone tells you your rotors need to be replaced, ask him what the spec is for your vehicle. If he can't tell you that and show you where your rotors don't meet the spec, either he doesn't know what he's talking about, or he's dishonest and is trying to get more money out of you for work you don't need. Either way, you don't want him or his advice near your car.

Beeman · #9 12/23/10, 09:59 PM

As long as you don't have a pulsation in the pedal when stopping and the rotors meet minimum thickness(should be cast or stamped on rotor) I don't have a problem with just replacing pads. I would use good pads, not lifetime guarantee from an auto parts supermarket. I use Wagner or Bendix quality pads.
If this is a 2wd van I would remove,clean and repack the frt. wheel bearings and install new grease seals. Be sure to clean and lube all caliper hardware with the proper lube. I use Sil-Glide from NAPA. The calipers must be free to float on the hardware. I also don't push fluid backwards thru the system, crack the bleeders before doing anything, it's easier with the calipers mounted. Then go ahead and remove then open bleeders and push pistons back.

mightybooboo · #10 12/24/10, 02:02 PM

Some rear brakes,disc,require a special tool to screw the calipers back in,harbor freight sells a kit that covers all.

Also agree the lifetime shoes can be a scam. I was talking to my guy about em,carquest,and they had a list as long as your arm when they wont honor them,including both sides have to have worn equally.He told me,its a scam really,nice he was honest about it,said buy the regular shoes.

Also,cheaper shoes mean softer shoes,they may wear out sooner but put less wear on rotors,that was very true.I usually do rotors with a change and the hard expensive shoes,did the midgrade this time (his advice),wore a bit sooner but the rotors are smooth as silk so I wont change them this time.Sure was nice of him to tell me what works,not what maximizes his profit.I give him all the business I can in return,win win situation.

I like really good brakes,and my rotors are cheap and easy removal,so I did back to factory spec with brake jobs with all new parts (not calipers,they stay good on this car),dont even need to this time.

Also agree,open bleeders and expel old fluid,I dont change mine but when I bleed them I do it til it runs clean and clear,guess thats close enough to a fluid change.On the old motorhome home had dirty wet fluid boil,lost brakes,yup,good idea to open bleeders when pushing calipers back in.Start bleeding from furthest wheel and work my way back towards master cylinder.

Harry Chickpea · #11 12/24/10, 06:17 PM

Gotter dun. Followed the advice here, had a Chilton book by my side. Rotors looked fine, the old pads were worn but not excessively so. Replaced them with Warners. Expenses - big C-clamp, pint of fresh brake fluid, pads, hex end for my socket set to remove the bolts, some brake cleaner. Might have a little air in the lines, dunno, tried not to but don't know about this stuff. Couldn't use the loaner torque wrench (wrong size drive, too long) so had to guess at how much force it took to get the bolts loose and then pull em back that much. Thanks guys.

agmantoo · #12 12/24/10, 06:30 PM

Harry
As long as you did not let the master cylinder empty itself as you were working I would not concern myself regarding air in the lines.

mightybooboo · #13 12/24/10, 06:52 PM

WTG Harry!

Beeman · #14 12/24/10, 06:57 PM

Quote:

Originally Posted by Harry Chickpea

Gotter dun. Followed the advice here, had a Chilton book by my side. Rotors looked fine, the old pads were worn but not excessively so. Replaced them with Warners. Expenses - big C-clamp, pint of fresh brake fluid, pads, hex end for my socket set to remove the bolts, some brake cleaner. Might have a little air in the lines, dunno, tried not to but don't know about this stuff. Couldn't use the loaner torque wrench (wrong size drive, too long) so had to guess at how much force it took to get the bolts loose and then pull em back that much. Thanks guys.

Good job!
Is it 2wd? I guess you didn't pack the wheel bearings if it is, if AWD the rotors just slide on and the bearings are sealed.
Torqueing the bolts is a good practice but not as critical on a standard GM type caliper. Did you remove the caliper slide bushings and lube all of the O-rings?

Harry Chickpea · #15 12/24/10, 07:13 PM

The master cylinder has two reservoirs. The small one was down to the bottom, but the bigger reservoir was fine. I saw a few bubbles when I topped the smaller one, which is why I'm a little concerned. However, the front brakes are doing fine, so I'm not obsessing.

I was surprised that a lot of the parts I was told to watch out for weren't there. The pads came without springs, so I reused the ones for the inner pads. The vehicle didn't have any springs on the passenger side outer pad when I removed it (checked a few times to be sure). The sleeves where the bolts go through were free and clear, so I left well enough alone there, and not be fooling with grease around brake pads and rotors. On the driver's side, the old outer pad had TWO springs and was worn much more. When I tried to fit the new pads in, no go, so I removed the outer springs and it fit fine. Braking seems even left-right. I can't even guess why the previous job was done the way it was. The fellow I had for a mechanic in Florida was generally on top of his game, so he may have had a legit reason.

I'm sure a lot of you guys could have done the job better and faster. I looked at the forecast here and decided to take advantage of the 45 degree temps with no sleet or snow, so I didn't dawdle too much.