Rear brake caliper loose

[RKnorr]

When I removed the right rear wheel I found that I could move the caliper up, down, left and right about 1/4". I found the plastic insulator had just about slid all the way off the securing rod. I decided that to not deal with it at the time and put the wheel back on without any further investigation. My questions are these; does the insulator help locate the caliper? Would the worn insulator account for the amount of play I found? Is there anything else I should be looking out for? What keeps the insulator in place?

[Eyelawdoc]

The rear calipers are held in place by an interaction between the caliper, caliper locating pins, the caliper locating plate below and behind the caliper and the clearance between the pads, caliper piston and rotor. The fitting tolerances of these parts are quite critical for proper function and operation of the rear caliper and rotor assembly. Improper assembly clearances, stuck pistons, corrosion and worn components can all adversely affect the way the various parts interact together and operate.

The free play you describe is excessive. The whole situation sounds dangerous! I recommend you get a copy of the FORD shop manual, as it details the specific steps and proceedures for the disassembly, inspection, diagnosis, repair and reassembly of the rear brakes. It is a lot more complicated than it looks at first glance. SVO front brakes are easy. Rears are a pain. When you read through it, you will see what I mean.

Fix it, or get it fixed NOW!. This is not something you want to let slide.

[RKnorr]

Fixed

It just so happens that I fixed this yesterday. I had to order a brake hardware kit and replaced the insulators which were shrunken and gooey. I don't know why they deteriorated the way the did but I suspect that somebody put grease or something on them. I had to clean the locating pins and the caliper with paint thinner to remove the old insulator and then clean the same parts with soap and water to remove the paint thinner so I wouldn't destroy the new parts. The calipers no longer are loose and they don't drag.

[kiwi]

Suspect.....

RK, I WAS going to say something because a lot of people go to the SS insulators, but I don't know my brakes that well....

[Eyelawdoc]

Glad to hear it is fixed! Lots of people will incorrectly use petroleum based chassis grease as a lubricant, which causes the rubber insulators to rot. Also, chassis lube does not have the temperature tolerance to handle the heat generated here. It can cause a real mess!

The proper lubricant is a high temp silicone grease. Same stuff you use on electrical connections. You can buy a tube of it for $6-$10.

For street driving, the replacement rubber caliper pin insulators work just fine. Autozone sells tham as a rear brake hardware kit with a new anti-rattle clip for about $15.00. It's cheap and easy to change them out when you do the pads.

[CP86SVO]

Silicone dielectric grease for electrical connectors IS NOT the same as brake lubricant...

Get the stuff that specifically says it's a brake lubricant!

WS

[RKnorr]

Its all good information. Thank you everyone.

[kiwi]

RK?

Caravan?......Reunion......that wednesday of the week.....
BTW/ Glad to hear brakes are straightening out....

[Eyelawdoc]

Beg to differ with you CP86SVO, but they're both the same stuff.

1988 Ford Car Shop Manual, Vol B, 1 of 2, 12-25-6: Brakes, Disc-Single Piston, Sliding Caliper-Rear: Installation, states as follows:

"1. Apply Silicone Dielectric Compound D7AZ-19A331-A or equivalent to inside of slider pin boots and to slider pins"

The high temperature properties of dielectric grease and and its non-petroleum, silicone base make it an ideal lubricant for brake parts. It is often sold under a different lable as brake lubricant.

For me, it is cheaper and more convenient to buy it in a resealable tube than the small one-use packets that Autozone and others sell fo a buck a shot. The Motorcraft part number for D7AZ-19A331-A is WA-10. It comes in a 3 ounce tube.

[CP86SVO]

Well, after using the Ford Dielectric Silicone grease, as per Ford service manuals, for several years on my 1988 5.0L notch with the Ford Motorsport M2300C rear disc brake conversion, I can definitely say that the dielectric grease does not work very well. I was always wondering, despite regular, twice yearly servicing of the cailper pins, the pins would always seize in, requiring heat to remove the pins and new pins/hardware everytime. When I switched over to brake lubricant (which does not look like the Ford Dielectric grease) on the advice of a mechanic friend of mine, my problems went away. I guess on the "Wet" Coast of Canada we get lots more rain and snow. I didn't get this problem on my SVO since it's a sunny day car only...

HTH WS

[Eyelawdoc]

Well, I guess the operating conditions up north in Canada are considerably more severe than here in sunny So Cal!Do they salt the roads there in the winter?

When I did the first pad replcaement on my 84 SVO (original owner) at 180,000 miles the caliper pins and rubbers were in good shape. Same thing for my Mark VII when I changed out the original rear pads at 98,000 miles.

When you go into an autoparts store here and ask for brake lube they will sell you a small plastic capsule filled with silicone grease. Some premium replacement pads even come with some packed in the box.

I would imagine what you are using has something in it to offer improved moisture protection and water resistance. How about sharing the brand info with us, I'd like to check it out.

[ediii]

180,000 miles on the original brakes?!?!? What did you do, drag your feet to stop the car most of the time? Is this Fred Fintstone?

ED

[Eyelawdoc]

Actually, 180,000 is for the rear pads. The fronts went until 203,000. The car sees a lot of freeway driving, not much need for braking. The original clutch went 204,000. Mileage now is a little over 218,000.

[CP86SVO]

The two lubes I have used with success are:

1. Ford Disc Brake Caliper Slide Grease D7AZ-19590-A

2. AGS Sil-Glide Brake Lubricant

I suspect that they are very similar to each other i.e. high temperature silicone based lubricants...the AGS brand of dielectric silicone grease mentions that it's a high temperature grease, good to 400 degrees F, but I think brake temperatures can easily exceed that when open tracking...

HTH

WS

ps. they do salt and sand the roads here in winter, if and when it snows...

[Eyelawdoc]

Thanks! I'll give it a try.