Late model retracting calipers again??

[Mac]

Can anyone say if most all modern calipers are the troublesome retracting type that require the quick-take-up style of MC?

Would these calipers be found on rears as well as fronts? I've read these calipers date back to the early 80's for rolling resistance issues with gas mileage. Others say that they came out with ABS which is more recent.

I'm concerned about the OEM units I plan to use on my `95 T-Bird rear.

Thanks y'all

[Mac]

Is this a tough question?
Dumb question?
Is this a problem exclusive to the GM metric calipers? Should I not worry about these `95 Ford rear units?

Somebody? Anybody?

[enjenjo]

I don't have an answer.... yet

I do know several people who have used the Explorer rear discs with no problems.

GM started using them in about 1982.

A good way to identify a car that used them, in the master cylinder bore specs, there will be two diameters listed, with the larger considerably bigger than the smaller.

[btrc]

Is this a problem exclusive to the GM metric calipers? Should I not worry about these `95 Ford rear units?

You've got me curious.  I've never heard about this problem but would like to know more because I have both the GM metric calipers in front and the Ford IRS calipers in the rear of my '37.

[Mac]

Bob, maybe you missed this post.
t=877 IRS calipers in the rear of my '37.[/quote]
Be sure to follow Wayfarer's link to the HAMB thread.

Mac

[Mac]

Durrh, looks like I dunno how to copy and paste a link to the old post.

Anyway look for Sinistr's post back on June 4th.

Mac

[Mac]

I don't have an answer.... yet
E-jo, I'm heartened to know your on the case.



A good way to identify a car that used them, in the master cylinder bore specs, there will be two diameters listed, with the larger considerably bigger than the smaller.

I know disc/disc setups will typically have M/C bores of like 1 1/8" but do I understand you here as saying that a parts store will have 2 listings for a given make, model & year? As if the retract-o calies and QT-up M/C deals are options or otherwise only sometimes used? :?

Mac

[enjenjo]

As if the retract-o calies and QT-up M/C deals are options or otherwise only sometimes used?

No. The regular master cylinders are listed as Bore size 24mm. or bore size 1" The quick takeup master cylinders are listed as bore size 24/36mm or 1"/1 1/4" The master cylinder bore is actually stepped to get a great volume of fluid quickly, moving the calipers out, and then the smaller bore applies the pressure. The piston is more complicated too, the outer part bottoms out, and the inner keeps moving. Also typically the rear part of the master cylinder is for the front brakes, rather than the rear as it used to be.

[SinistrV6]

[You've got me curious.  I've never heard about this problem but would like to know more because I have both the GM metric calipers in front and the Ford IRS calipers in the rear of my '37.

That's the same set up I have.  What master cylinder did you use?  Any problems?


After doing some research on the "small" GM calipers, the best answer I've gotten is if it doesn't say "Metric" on the caliper it won't be a problem.
Other than that, all I have is a few GM part numbers.  When I looked up the parts on NAPA's website, they list the same part for the '78 Monte as the '85 Camaro so, who really knows?