Brake job advice

taylorlambert · #1 07/25/10, 12:54 PM

I have a brake job question, I m about to replace the disc brakes on the front of my wifes 02 Ranger. I had a know it all friend tell me that I need to bleed the bake bleeder then pry the pads back or it will damage the antilock sensor. I though the only time you bled one was if the resivoir had been filled up when the fluid got low as the pads wore and the caliper extended. I used to do my own brakes on my cars in highschool and college but thats been 12 years ago.

I do the disck brakes on the Macks at work but they are air brakes and you just back off the adjusters.

I would take it to a shop but lately there been several note brake ailures from some of the local shops where poor workman ship was involved with things being let of brackets not being replaced, Rotors not being installed. I have a friend that does great work but theres a 2 week wait now.

Beeman · #2 07/25/10, 01:59 PM

Quote:

Originally Posted by taylorlambert

I have a brake job question, I m about to replace the disc brakes on the front of my wifes 02 Ranger. I had a know it all friend tell me that I need to bleed the bake bleeder then pry the pads back or it will damage the antilock sensor. I though the only time you bled one was if the resivoir had been filled up when the fluid got low as the pads wore and the caliper extended. I used to do my own brakes on my cars in highschool and college but thats been 12 years ago.

I do the disck brakes on the Macks at work but they are air brakes and you just back off the adjusters.

I would take it to a shop but lately there been several note brake ailures from some of the local shops where poor workman ship was involved with things being let of brackets not being replaced, Rotors not being installed. I have a friend that does great work but theres a 2 week wait now.

Before anything open the bleeder screws and close them, it's easier to find out now if you can do it or if they are frozen. Then go ahead and remove the caliper and then open the bleeder screw and push the pads back allowing all of the "pushed back" fluid to come out of the bleeder screw. This stops all of that dirty fluid from pushing back into the master cyl. and anti lock brake control. This should be the procedure anti lock or not. I always suction out the master cyl, wipe out the resevoir and refill with clean fluid also. Back to the caliper. Clean all caliper mounting hardware and whatever the caliper slides on, they float and are not mounted rigid. Lube all rubber with Silglide or something similar, lube all metal with anti seize compound or similar.

Ray · #3 07/26/10, 08:06 AM

All you need to do is get a large C clamp and leave everything alone just compress the piston back into the caliper, be sure not to damage the rubber sleeve. The fluid will go back into the master cyl. fluid reservoir, and you will not need to bleed anything because no air will be allowed into the sys. If you take the brake hose off or open the bleeder valve then you will have to be sure no air got into system by bleeding. When doing rear disc brakes they may be different as the emergency brake cable hook up systems varies greatly from brands. so you'll need to find out which way its put on, some have a separate little shoe brake sys, some have the piston screw in and out, etc, and the C clamp method doesn't work on the screw type. but they are all really simple and only take about 45 minutes to do the complete front if you have everything ready, if things go nice maybe under 30 minutes to do the front of a car! I always use the cheep pads because some of the metallic hold too much heat and can cause the rotors to warp, especially if they've been turned down. Just an observation of my own, best wishes, ray

mightybooboo · #4 07/26/10, 01:01 PM

Good comments.I open the bleeder screw to get rid of old fluid.Just did my front brakes yesterday.But Beeman apparently knows of vehicles that can damage anti lock systems by backfeeding pressure,think VW is immune to that though.But why risk it?And who wants to keep the old fluid around anyhow,it gets moisture in it and will rust out your system,get rid of it and you will not regret it.

I also have the kit that screws in the piston on rear calipers,its cheap at harbor freight and works for all cars they say,does VW Jetta,has all different sized pieces.

Now I like the hard metallic shoes,got super miles on last set,but forgot what brand I used,hope this set does as well.As Ray says,they tear up rotors but my rotors are so cheap to buy I replace em with each brake job,its simple ON MY CAR. Some rotors,like my truck,SUCK to replace so take Rays advice and apply it as your situation warrants.

BTW,my fronts took 2 hours but I had to find the parts,drag out jack,replace on a hill,find an 18 mm socket,that stuff cost me time.To actually pull rotor and shoes,15 minutes max per side.VW brakes,surprisingly user friendly and shocking because so much of that car isnt.

Beeman · #5 07/26/10, 02:11 PM

All you need is one problem that could have nbeen avoided with 2 minutes worth of work to convince you to open the bleeders. Do enough brake jobs and you'll have the problem. Also if you push the fluid back into the MC you have to suction the resevoir before or you'll push fluid out the top and all over the MC and the floor.
Rotor "warpage" is many times caused by not cleaning the mounting surface of the hub that the rotor slides on. The slightest bit of rust or dirt will effect the clamping of the rotor. Also use a torque wrench to tighten wheels. The lug nuts hold the rotor or pull thru the rotor. Uneven clamping forces especially from repeated heat/cool cycles will effect the rotor.

Cleanliness is the secret to good brake jobs.

mightybooboo · #6 07/26/10, 05:15 PM

Again,more good advice.Yep,I torque mine to 89 lbs per manual,and it seems NOBODY actually torques those lugs.They will tell you they will,then the tire guys DONT as a rule and yep,warped rotors.Really ticks me off these morons screwing up our rotors,GRRRRRR!!!!!!!!

foxtrapper · #7 07/27/10, 06:42 AM

Any time you push the pistons back in the caliper, it's a good idea to open the bleeder and push the fluid out of the system, and not back up to the master cylinder. Generally, the fluid is funky and that's not good stuff to backfill your system with. Many times there is gunk and even rust sitting back in the bores of the caliper because the piston hasn't been there for years. When you push the piston back, you're pushing it back to where it hasn't been, scraping the rust and gunk off the walls. You don't want this stuff floating around, especially inside an anti-lock actuator. So do just crack the bleeder and move the pistons back.