Changing Discs & Pads on '88 N/A w/ABS

[Kai]

As stated in the topic - i've got me some 'new' pads and discs so its actually safe to drive more than 10 feet

Thing is - I've looked at the TSRM and it says under BR-25 section 10 (Installing Cylinder) that when installing 'draw out a small amount of fluid from the reservoir' - how is this done exactly?? I remember on my XR4x4, i had to have someone depress and hold the pedal while brake fluid came out all over the floor, then tighten the nut so the pedal could be released.

As for depressing the piston with a 'hammer' - um, last time i had to depress a piston in a brake caliper - it took two people and i busted the piston boot...

 

[Nick M]

What are you talking about? Changing discs and pads doesn't require hydrualic work unless there is a caliper problem.

Take the lower bolt out on the caliper and loosen the uppper. Lift the caliper. If it doesn't push in with a caliper press tool, it is hand held and usually 5 bucks, then you have a frozen piston. But it is usually the slide. Put in the pads. Bolt the caliper back to the bracket. Remove the braket from the knuckle with caliper intact and remove the rotor.

 

[Kai]

Well all previous cars i've worked on require the brake system to be bled after you move the piston, otherwise you end up with Air bubbles. If its just a matter of bolts - then it'll be a cakewalk, but the TSRM said to do something with the fluid as well, so i thought it safer to ask than just do and have something go wrong when i slam on the anchors...

 

[Steve_N]

Bledding the system isn't required. The reason to remove some fluid is because when the claipers pistons or pressed back in it pushes fluid into the reservoir. If the reservoir is full it spills out & creats a small mess. To remove the fluid I just use a turky baster & siphon it out into a clean cup. I poor it back in after I'm done pressuring up the system by tappin on the brake peddel a few times.

 

[mrnickleye]

What the TSRM is refering to is this.....

When you squeeze, or pry, or press, (whatever) the caliper piston back into the caliper to make room for the new pads, the fluid will go back up into the master cylider resevior. If you don't remove some fluid first it will over flow onto your engine bay.

Also, an UPDATE on this process.

You actually should crack open the bleed screw of each caliper to let the fluid out. I put a 12" piece of vacuum line on it and put the end into a coke bottle to collect the fluid.

Pushing the fluid (the old way) back into the master cylinder can cuase brake problems. You would be pushing fluid against the 'main flow direction', and possibly pushing contaminants into the master cylinder valves. And worse ($$$$), into the ABS valving system.

Uh... how do I know ?? (you ask), because I'm an ASE master certified tech for 22 years. 5 years at Toyota dealer.

I've seen it happen a few times to mechanics that were in a hurry to make the $$, and cut corners. I care about my customers, and just do it right. Less troubles or 'comebacks'.

Also...you have to remove the caliper to replace the rotor.

Use some Synthetic disk brake grease on the slides and pad to caliper contact points.

 

[Kai]

Aah - see, thats the way i'd prefer to do it, opening the bleed screws...just seems....'safer' somehow. However, if i do that, do i have to worry about airlocks or is the system one way?

 

[Nick M]

The cap has a sensor in it. That light tells you when to put pads on. You don't want to go to low, but you won't if you replace them when the light comes on.