Front brake overhaul tips?

[DAEDALUS]

On Monday I was hoping to do a brake "job" on my '90 Q and I have now been promoted to a brake "overhaul". Had the rotors turned (geez, they took off about .020 each), and bought new pads and hardware. As I was pushing the pistons back into place, one of the rubber dust boots began leaking brake fluid, making a somewhat gurgling/squirting noise. So now I've removed everything. Calipers and pistons look good. Brake lines will will be replaced with stainless. I need any tips you guys might have about replacing the seals and boots. Looks like I'll first have to replace the seal. What happens next? Do I attach the dust boot to the caliper first or the piston first? What's the trick here, if any? Thanks a lot.

[Q45tech]

We don't rebuild the calipers [too much liability] we just replace them with factory rebuilt units [letting someone else shoulder the risk].

[AZhitman]

Uh Oh. Have fun DAE - Hopefully someone will chime in here.

BTW, who has the best price on stainless lines?

[jefftrexler]

Well on nopi.com they have Goodridge stainless steel braided brake line kits for $110. Not too shabby.

[DAEDALUS]

What's the word on the Goodridge lines? I'm thinking of going to Earl's, only because they're (very) local to me, I can have the parts made in a day, and the rumor is that walk-ins sometimes get some pretty good deals. I will inquire about group pricing while I'm there on Thursday.

[AZhitman]

Tell us more - sounds promising!

[DAEDALUS]

See thread entitled Stainless Steel Brake Lines for 1st Gen Qs.

[DougQ45]

Daedalus: First clean the cut out for the piston seal inside the caliper body real good!! Then put the piston seal in, and then goop up your piston with a little vasoline to help the piston in. Gently insert the piston in the bore (may help if you give a twisting motion) and push it in maybe 60-70% of the way in. Don't gorilla it in or you could snag it. Then I beleive you place the snap ring in the dust boot, and turn the boot kinda inside out, then insert the dust boot snap ring into your caliper. Slide the dust boot back outside in and around the piston and you are done. If you need any first hand help let me know as I owe you one. Can also help on your fuel pump--- bet it can be done in about an hour!! Doug

[DAEDALUS]

Thanks for the tips Doug, and for the offer! I think I'll be OK, I'll be sure to lay down some old sheets around the tank in case I don't get all the pressure out. I doubt I can do it in an hour, including R&R of the seat and lid, but I won't be in too big a rush. I might take this opportunity to remove the front seats while I'm at it and give the carpet a thorough cleaning front to back. Front brakes are a bit different from the rears...no snap ring. I sure as heck can't explain that design difference.

[texasoil]

NEVER NEVER put ANY petroleum product (oil, grease, solvent, vasoline) on or around any part of the fluid handling system. It will rapidly destroy the seals and hoses.

Use only new brake fluid as a lubricant.

[DrewQ45]

Daedalus,

What you have there might not actually be a problem so no reason for all that work... of course new seals can't hurt though.

When being pushed back in, the piston must be perfectly level with the caliper else the leakage will occur. If there is any lean at all, fluid will escape past the seal. Once you push it back in, it should be okay and leaking stops. I assume you're using a channel lock open to it's widest setting or a C-clamp.

Putting an old brake shoe on top of the piston before compressing it usually keeps it level enough to avoid this. (providing that it was evenly worn)

Remember to check the fluid level in the cylinder when done.

..Drew...

PS: Upon reading your post again (I'm a bit slow sometimes) I realized that you've already pulled it all apart.

Don't mean to scare you but it's a bit*h putting that thing back together so the split ring is seated in properly while not pinching the rubber boot or having it pull out of the groove. You must have this thing no less than perfect!!!!

I brought a seal kit from Infiniti which had everything including a tube of red grease for lubing the slide pins.. I managed to do it manually but it took me hours of trying before I learned how to do it perfectly. (I would explain, but don't remember the process) I think there is a special tool for this which may make it easier else you can take the caliper to a shop just to have that part done?

..Drew...

[DAEDALUS]

Thanks Drew. The fronts don't have the ring, and they weren't too difficult. I did buy the seal kit with all the little grease baggies. Yes, they're very complete. Pink stuff on the pins, red stuff on the pistons. The seals and boots went on without too much effort (used a quick-grip) and so far they haven't leaked a drop that I can tell. I will do the rears eventually. Bought the seal kit for that too, but I just put new pads on, so I'll likely wait till the pads wear out to do those seals.

[firstq]

DAE - I am planning to fix my front Caliper issue as well - this past summer tryin to bleed the brake fluid, I managed to pop out one of the pistons by mistake (front driver side caliper).

So r u saying there is no metal clip that keeps the piston boot in place?

Thanks

[Q451990]

BTW, who has the best price on stainless lines?

I'm happy with the lines I bought from http://www.techna-fit.com/ - seems like they were $115 or $120. The collar around the fittings, that should help prevent sheering of the SS braids at the junction - and clear plastic coating (to keep dirt from lodging between the teflon lines and braids and causing abraisions) both sold me on their product.

Heath

[DAEDALUS]

DAE - I am planning to fix my front Caliper issue as well - this past summer tryin to bleed the brake fluid, I managed to pop out one of the pistons by mistake (front driver side caliper).

So r u saying there is no metal clip that keeps the piston boot in place?

Thanks

Correct, no ring on the front seals. You need to slide one end of the seal over the piston, insert the other end into the caliper seal groove, and then carefully work the piston into the caliper while keeping the seal seated. It took quite a few tries each time...just a really frustrating job.