MGB & GT Forum

?, Why do they say in the adds for the frnt. cal. rebuild kits to avoid splitting apart the cal.? They seem to always say that in the add for the small seal that sits between the 2 sections.

There's been threads posted that say that the bolts holding the caliper together are designed to stretch a certain amount, and when reinstalled they don't work as they should. Many have done it with no issues, but I would read u on it before taking the chance.

---

1973 MGB: Blow through supercharged, intercooled, 10psi boost. VP12 cam, aluminum flywheel, 8.9:1 compression. Black label OD, Saab 15” minilites. Goes a lot better than it looks.

When you split a caliper it is often prone to leaks afterward.

---

“Ideological certainty easily degenerates into an insistence upon ignorance". Daniel Patrick Moynihan

In any debate, the side which strays from civil discussion is usually the side that lacks confidence in its debate position or in the merit of their arguments. Making personal attacks on the opponents instead of staying on the subject is also a sign of weakness.

Anyone who feels compelled to respond in kind to any perceived slight is often suffering from narcissism.

An incompetent person splitting the caliper and losing that small seal between the two halves could result in the serious injury or death of those in the car and anything else they may hit. However, read up on it and be sure if your rebuild kit does not come with that seal, buy a new one. They are readily available and cheap. Everything else is pretty straight forward. Unless a piston is froze, then it gets a little more difficult, but a grease gun will cure that issue.
Note: try to avoid ruining the metal ring on the way out. Often times, the new rings they send are of such cheap quality that they warp beyond use before you ever get them in the groove. The originals are much stouter and easier to use if you don't bend them badly. And purchase some PBR rubber grease or other similar product.
-Noah

Thank all of you for your answers. I split the cal. apart- glass beaded them (Yes I did cover the sealing surfaces) and then had them zinked. I was just wondering if there was some unknown magic about splitting them. The whole process seems quite simple. As to the bolts, I see no reason why they should not be reused. I see no signs of ware or fatigue.

Dave I think the non-splitting of calipers is a bit of an urban myth that may well have been started by Lockheed way back when. You have to split them to replace that small seal. My understanding is never mix halves. As to the bolt I suggest if you are interested you search out my caliper bridge bolt topic. There's a school of thought that these are a once only bolt. In the end I decided discretion is the better part where brakes are concerned and bought new ones. They are a 'special' bolt not from the hardware shop and coincidentally I will be changing my bolts today.

---

Mk1: CKD 11/66 first registered 8/5/67; owned since 3/77. 18GB +40 balanced. Peter Burgess BVFR head. Piper 285. 123. FidanzaFW. 4synch c/r box. Lots more as I did a nut and bolt rebuild; finished 2015. Tartan Red.

GT: December '78. VW Golf guards, flush fit front and rear valances. Torana XU1 vents, frenched indicators & Mk1 rear lights. 'Worked' Rover V8 with Monsoon ECU for EFI. GM4L60E, Lokar tiptronic & Quick4 controller. Vintage Air A/C. FC IFS. CCE 4 link rear. Salisbury with Quaife. Jaguar Storm.

The caliper rebuild kits do not come with a new seal for the channel between the halves so they used to say not to split them in case you lost or damaged that seal. For a long time they weren't readily available but about 4-5 years ago, one of my pals borrowed a couple of new old stock ones from me and had a lifetime supply of them made. He thanked me by sending back my originals and a bag full of them. Since they're now available and inexpensive, the reason not to split them has gone away. Let me know if I can help or if you have new seals already. Thanks. Basil 707.762.0974 basiladams@yahoo.com

---

Basil C. Adams
1956 MGA Coupe (Show Car)
1957 MGA Roadster (Driver)
1958 MGA Coupe (Racecar)
1959 MGA Coupe (unrestored)
1960 MGA Coupe (unrestored)
1960 MGA Roadster (Driver)
MKIII Elva Courier (E1056)
1967 427 Cobra
1972 Alfa Romeo Montreal
A coupla late MGBs
1960 Austin Healy BN7
More Cars than Brains

My urban myth quote above was troubling me so I went back into search - this seems to be the reason the 'never split calipers' story arose.

---

Mk1: CKD 11/66 first registered 8/5/67; owned since 3/77. 18GB +40 balanced. Peter Burgess BVFR head. Piper 285. 123. FidanzaFW. 4synch c/r box. Lots more as I did a nut and bolt rebuild; finished 2015. Tartan Red.

GT: December '78. VW Golf guards, flush fit front and rear valances. Torana XU1 vents, frenched indicators & Mk1 rear lights. 'Worked' Rover V8 with Monsoon ECU for EFI. GM4L60E, Lokar tiptronic & Quick4 controller. Vintage Air A/C. FC IFS. CCE 4 link rear. Salisbury with Quaife. Jaguar Storm.

Thanks Barrie and Basil for this info. I had always wondered about this.

An opportune topic - actually I'm getting ready to rebuild my calipers, I have new pistons, seals and the little square "O" rings to go between the caliper halves. What torque do people use on the bolts when re-assembeling the halves? Because they were never supposed to be split, the factory never gave a torque spec for them.

Bob

There has been at least one reported case on this forum of bolt failure, only resulting in a need to change underwear. Hopefully this won't happen to those individuals that cure a shuttle leak with a bolt where the failure switch used to be. If the caliper uses stretch/torque setting or whatever they are called, they shouldn't be reused. These type of bolts are designed to plastically deform and get thinner and weaker with each use. Someone, maybe a Rover tech, described them as a product of the machine age to assist accurate assembly line torqueing by machines. Or maybe someone figured out a way to sell us expensive sets of bolts. In any case and in the interest of safety, use proper new bolts. IMO, there shouldn't be any need to splitting the halves. But if you must, use new seals and bolts.

@#10 read the 'this' in #8 - last line. FWIW I did mine to 50 plus a bit more and a dab of threadlocker - today (see #6)

---

Mk1: CKD 11/66 first registered 8/5/67; owned since 3/77. 18GB +40 balanced. Peter Burgess BVFR head. Piper 285. 123. FidanzaFW. 4synch c/r box. Lots more as I did a nut and bolt rebuild; finished 2015. Tartan Red.

GT: December '78. VW Golf guards, flush fit front and rear valances. Torana XU1 vents, frenched indicators & Mk1 rear lights. 'Worked' Rover V8 with Monsoon ECU for EFI. GM4L60E, Lokar tiptronic & Quick4 controller. Vintage Air A/C. FC IFS. CCE 4 link rear. Salisbury with Quaife. Jaguar Storm.



Edited 4 time(s). Last edit at 2014-10-20 08:03 AM by MGB567.

Lockheed used to sell a caliper bridge repair kit. It contained 2 bridge bolts & the square O ring. Now & then you will see NOS kits on Ebay.