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who rebuilds front calipers?

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maxwedge5281

maxwedge5281

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i am expecting delivery of my minilite bolt on wheels in a few more weeks. since i will have to change out the front hubs i thought it would be a good time to rebuild the calipers. who do you guys recommend.... preferably in the southeast as i am in south carolina. i appreciate any advice or recommendations!
 
I have used White Post restorations in Virginia with very good results.
 
Rebuilding calipers is about as difficult as changing your socks , why wouldn't you just do it yourself ?
 
Healey Nut said:
Rebuilding calipers is about as difficult as changing your socks , why wouldn't you just do it yourself ?
Click to expand...
I did mine, replaced pistons and seals. No big deal. The calipers were fine, just corroded pistons. The seals weren't leaking, but I replaced them anyway. I used the standard pistons, because the old ones were in there for over 30 years. I'm 70 and don't plan to live to 100. I also plan to change fluid every five years or so instead of never in 34 years.
 
I used Apple hydraulics when I did my TR 3 14 years ago.

don
 
Guys

All I would suggest is that once installed you check the quality of the build by standing on the brakes a few times before you move the car. I installed a set of refurbished replacement calipers only to find one of them leaking all over the place. It turned out that the seal had been nipped during the refurbishment - by a specialist!

:cheers:

Bob
 
Bob Hughes said:
Guys

All I would suggest is that once installed you check the quality of the build by standing on the brakes a few times before you move the car. I installed a set of refurbished replacement calipers only to find one of them leaking all over the place. It turned out that the seal had been nipped during the refurbishment - by a specialist!

:cheers:



Bob
Click to expand...

That can happen to any one it should have been found before it was sent back to you.

Don
 
Don

I agree, they should have been tested but they could not have been.

There was a history - they were originally put on a car by a restorer for a lady who subsequently removed the car from said restorer and put it in the hands of another restorer ( do not know why). She then upgraded the calipers to a BJ8 caliper so they were sold to me at a knock down price but had never been used.
The second restorer repaired them for me at no cost and that is how we found that the seal had been nipped.

All I am saying is be careful and check them yourself once they are on the car no matter who repairs them.

:cheers:

Bob
 
are bj8 calipers a direct fit on the bn7, bt7, bj7 cars or must the mounting be changed?
 
maxwedge5281 said:
are bj8 calipers a direct fit on the bn7, bt7, bj7 cars or must the mounting be changed?
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3000 disc brakes used a Girling Type 14 caliper which has a 3.25" spacing between mounting bolt holes. The BJ8 (I believe from chassis no 26705) switched to a Girling Type 16 caliper with a 3.50" spacing between the mounting lugs. The BJ8 also switched to a thicker brake rotor. Denis Welch Racing sells the mounts to change to the 3.5 inch calipers. Not sure if you need to change to the thicker rotors, which also may mean changing to different wheel bearings at the same time and you may need to change the master cylinder as well as the BJ8 calipers have a higher fluid capacity than the Type 14s.

I doubt you'll get much improvement in braking by going to the Type 16s. You'd be just as well off using a good set of performance pads on what you've got. If you're still looking for a caliper rebuilder you can ship them to me and I'll drop them off at the place that did mine: https://kingkalipers.com/advantages.html

Or if you really want an upgrade, check out SteveG's Toyota caliper modification.
 
The mounting is changed: the brake backing plate goes away and a bracket mounts on the four bolts of the swivel axle.

If you're considering upgrading your BN6 to front disc brakes, the easiest way is to buy the kit from Denis Welch - this includes everything you need: brackets, calipers, hubs and rotors. Not sure whether they supply the braided metal hoses. The caliper supplied is an early-70s TR6 unit which has the 3.25" bolt centers but uses the larger cylinder & pad setup of the BJ8 Type 16.

After my own experience, I'd advocate adding the braided metal hoses at all three positions and swapping Welch's Delphi pads out for the Moss Classic Gold ceramic pads. If you do that (and break the pads in per instructions) you should not need to swap your 3/4" master cylinder for the 5/8" one used on the non-servo disc braked cars. Adding a servo also shouldn't be necessary. My car has 4-wheel disc brakes, the 3/4" cylinder, and no more pedal pressure than it had with 4-wheel drums.

Addendum: Welch kit includes all three braided-metal hoses.
 
steveg said:
...After my own experience, I'd advocate adding the braided metal hoses at all three positions and swapping Welch's Delphi pads out for the Moss Classic Gold ceramic pads. If you do that (and break the pads in per instructions) you should not need to swap your 3/4" master cylinder for the 5/8" one used on the non-servo disc braked cars. ...
Click to expand...

Peter Roses informs me this is not correct -- even with the ceramic pads and braided hoses the pressure with the 3/4" cylinder was too great and he needed to go to the 5/8" MC and different rear wheel cylinders.

The fact that I did not experience the same issue, I attribute to the combination of larger and smaller cylinders in the 4-piston Toyota front calipers -- this configuration must somehow require less pedal pressure.
 
i finally got around to ordering the parts to rebuild the front brake calipers to include stainless pistons. i am assuming that i will not have to seperate the calipers to rebuild???? experts is this a correct assumption?
 
Yes you have to separate to put in the new o ring. pretty simple. clean everything and consider using new grade 8 bolts with locktite when you put it back together.

jerry
 
maxwedge5281 said:
i finally got around to ordering the parts to rebuild the front brake calipers to include stainless pistons. i am assuming that i will not have to seperate the calipers to rebuild???? experts is this a correct assumption?
Click to expand...

MGA Guru has a good article on splitting the calipers:
https://mgaguru.com/mgtech/brakes/bt104b.htm

This includes the Moss PN #180-285 square section o-ring which seals between the halves. The part is listed for cars other than the big Healey.

Not splitting the calipers is Girling's recommendation, according to Pegasus Auto Racing, but they do sell the square o-ring. MGA Guru says Girling would rather sell you a whole new caliper. Go figure.

With them split, cleaning and rebuilding is easy.
 
I don't think splitting the calipers is usually considered part of a simple rebuild, that is why the seal between halves is not part of a regular rebuild kit. I suppose it does make putting the new pistons and seals in a little easier. I also suppose the seal between the halves could fail and cause a leak (making a case for replacing it), but I have never had it happen or even heard of it happening.

I had a heck of a time rebuilding the caliper on my TR250 (same caliper is used on a BJ8) spent a whole afternoon trying to get the dust seals on, the set I got were too big/thick, making it near impossible. I ordered another set, it was easier, but still involved a bit of time and effort and bad words to get them on. Go in thinking it will be hard, then you can be pleasantly surprised if it goes smoothly, better than the other way around....
 
The Girling calipers used for my Tiger and Alpines I've always split. I find it's reall the only way to clean out the grooves for the dust seal and piston O ring completely. I've used a Dremel tool with a small cutoff wheel to route out the dust groove, hard to do any damage to the cast iron as it's easy to tell when it starts to touch it and not rust and dirt. Then a small circular stone in the piston seal groove to remove rust spots and slightly polish it, once again hard to do damage as the stone is too soft to cut unless you really try. Then reassemble with new seals and pistons, which if it takes more than a couple fingers to push in the seal is wrong or out of place. Then bolt the halves back together. Never had leak problems myself.
 
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