Replacing brakes -- lube the inside or outside of the caliper bushings???

Ewout_vB · 05-09-2009, 09:45 PM

So, I decided to do it correctly this time around

and lubricate the parts needed while changing the pads/rotors etc. Anyway it was suggested that I lubricate the slides, but also the caliper bushings. Do you lubricate the inside of the bushing where the bolt slides in or the outside that the boot sits over? (or both?) Any help would be great!

ZeeJay1997 · 05-09-2009, 09:49 PM

Outside. I use white lube

Ewout_vB · 05-09-2009, 09:59 PM

Do you guys suggest something like "Disc Brake Quiet" or other stuff like it that you put on the back of the pads against vibrations?

JrMechanic · 05-09-2009, 10:23 PM

Quote:

Originally Posted by ZeeJay1997

Outside. I use white lube

He says he uses white lube.

ZeeJay1997 · 05-09-2009, 10:24 PM

Quote:

Originally Posted by Ewout_vB

Do you guys suggest something like "Disc Brake Quiet" or other stuff like it that you put on the back of the pads against vibrations?

I tried it and didnt have good results. Only works for a month or so.

ZeeJay1997 · 05-09-2009, 10:25 PM

Quote:

Originally Posted by JrMechanic

He says he uses white lube.

let me in on the joke...

JrMechanic · 05-09-2009, 10:30 PM

Just poking some fun at ya dude.

ZeeJay1997 · 05-09-2009, 10:39 PM

I fail to see how white lube is funny...I can take a joke, I just don't see any humor...

How about explaining it to me here in this open forum.

5-90 · 05-09-2009, 11:41 PM

Chew on it for a minute - "white" and "lube" in the same sentence, along with a bunch of dirty-minded ****ers...

For the OP, I usually just burnish dry graphite into sliding surfaces of brake parts, using a metal "ball-on-a-stick" (remnants of an old "mirror-on-a-stick" that I lost the mirror part of years ago.) Works rather well, and doesn't collect brake dust like white grease or brake grease does.

I inspect stuff like that annually - so I just burnish more dry graphite in while I have it torn to bits.

I may eventually take the caliper support brackets and drum brake backing plates off and coat them with a bake-in PTFO/MoS2 dry coating one of these days, but the dry graphite has worked well for me. Any smooth steel surface can be used to burnish the graphite in - you can use, say, an old pushrod (just work a bit away from the hole drilled in the end.)

ashbrooke · 05-10-2009, 07:38 AM

I just did the brakes on my 2004 Cherokee this weekend. Two of the pins on mine were seized up, so I ended up pulling them off and cleaning the inside of the bushing and pins.
I just used my Mobil 1 grease and everything so far works fine. Not sure how everyone else feels about using that type of grease though.
Either way, I suggest definitely pulling the pins and applying some type of lubricrant.

hydra · 05-20-2009, 08:28 PM

Quote:

Originally Posted by ashbrooke

I just did the brakes on my 2004 Cherokee this weekend. Two of the pins on mine were seized up, so I ended up pulling them off and cleaning the inside of the bushing and pins.
I just used my Mobil 1 grease and everything so far works fine. Not sure how everyone else feels about using that type of grease though.
Either way, I suggest definitely pulling the pins and applying some type of lubricrant.

Yup.

I can't speak for the XJ...but for the ZJ, the 1995 factory service manual definitely says to lubricate the rubber-bushings that the guides slide through; and calls for silicone grease or "Mopar multi mileage" grease.

Since switching to Stillen rotors and carbon/metallic pads at 70,000 miles, I've not had to touch the brakes until this week, at 210,000 miles....so I can't claim a big statistical-database of proof for my choice of lube.....but what I used both 10 yrs ago and this month was that blue/green "Ultra Disc Brake Caliper etc." synthetic grease by Permatex.

It came in gray bottle when I bought it in 1999.

Note that the caliper-guides run in a -rubber- 'bearing'....which is simply the mid-section of the boots that you see at both end of the guide....and that excessive brake-heating can cause that rubber to 'harden' and swell a bit.....which leads to guides which are almost impossible to move by hand.

How well such a "tight" guide moves during actual brake-application, I can't say...but if I had a 'dragging' problem, that's sure one of the first things I'd check...and fix, if it didn't slide freely with hand pressure.

Houndmaster1 · 05-20-2009, 08:36 PM

1st and foremost, only use brake lubricant on brake components. Petrolium based lubricants break down the rubber and plastic causing it to swell and create all kinds of trouble. Silicone is the apprprioate stuff to use. The brand we use at our shop is Sil-Glyde. You can also use it on the back of your pads to help with squeels. If you use ceramic compound pads, you wont have any noise issues. If you have already used regular grease, I would try to clean it off, or replace the hardware and do it right.

hydra · 05-20-2009, 09:04 PM

Quote:

Originally Posted by Houndmaster1

1st and foremost, only use brake lubricant on brake components. Petrolium based lubricants break down the rubber and plastic causing it to swell and create all kinds of trouble.... .

I think you're confusing the rubber boots/bushings that were asked about, with the rubber-parts INSIDE the brake-hydraulic system (like cups in the master-cylinder etc.)

The rubber boots/bushings on the caliper-guides most definitely are NOT damaged by petroleum fluids.

If they were, then every car on the road using them would be experiencing constant failures from every oil/gas/atf leak, as well as the unburned oil and fuel in the exhaust which surrounds them constantly, etc., etc..

Yes, the INTERNAL rubber parts of a brake hydraulic system ARE swollen by petroleum....but EXTERNAL exposed rubber parts, like these boots, are normal oil-proof rubber.

Also, synthetic greases do not generally affect materials in the same way that petroleum-derived greases do.

Note that the Permatex synthetic grease I mentioned is SPECIFIED for brake parts. It is specifically labeled and sold for the purpose.

fwiw, all of the low-end "white lithium grease" that I've ever seen has been petro-based; although I wouldn't be surprised to learn that someone makes a 'synth' based version of it these days. I do not use white-lithium for anything anyway, so I'm not up on what's on the shelves.

In any case, I wasnt reporting a 'problem'. My ZJ's rubber boots/bushings are like new, after 10 years and 150,000 hard miles with the Permatex synth grease in them.

The bottom-line, and what I was trying to get across in my other post, is that those rubber bushings ARE supposed to be greased (the original question), and to use a grease that's labeled specifically for brake-parts.

Houndmaster1 · 05-20-2009, 09:29 PM

Not to start a debate on brake work, but brake lube is for brakes. I am speaking from my own knowlege as a ASE master automotive tech. Everyone has there own ideas on automotive repair. Lucky for me, most know just enough to get into trouble. If everyone was an expert, I along with all other mechanics would be out of a job. Either way good luck with what ever products you use.