GT Brake restoration in the UK

[julieandtom]

Isuzu Club recently received a cry for help from the UK. The question was: Brake rubber kits fir front disc calipers and rear brake kits urgently required PLIZ.

Tom's answer was:
The front disc brake kit rubbers for PR91 are same as Jaguar XJ6 and E type centre piston with both piston and seal able to be used. (FDB52 Dunlop Sumitomo callipers). The original dust seals are no longer available.

If earlier Bellett GT PR90 early 1966 and before then pistons and seals are interchangeable with early E type rear callipers and are again Dunlop Sumitomo DDB 704 callipers. Again dust seals are no longer available.

FDB Calliper Pistons

There are two callipers, the early DDB704 split calliper as per the 1964 and 1965 S1 and S2 Bellett GT and homologation disc brakes and the later FDB52 calliper as fitted to all Bellett GT from 1965 to 1973. The early callipers are the same as the E Type Jaguar rear callipers both body, pistons and seals. DDB704 47x54mm.

The later FDB52 cars use a 2 x piston x 57mm (2.25”) diameter Girlock P/N 64325438 which is the middle piston in Jaguar 3 spot callipers.

Rear seals are just standard 7/8” seals

W/C Rear 7/8”

Cup P5151 - Repco

Boot P4388 - O ring alt

Kit K553s

O Ring seal OR 141216

[CQGT]

Thank you julieandtom. I have had calipers at my brake specialist for quiet some time. All 4 pistons were shot.
He was concerned that the locating pin in the centre of the piston was necessary and finding a piston with a pin
and diameter required would be hard to get.
I assured him that a piston without the pin would be ok and the Jaguar pistons would fit. I did some research for a
57mm piston through Protex listings and found a few but were too high and would have to be machined down to suit.
The part number that you have given (64325438) was the closest although 1.11mm higher. With not shimming and
possible having to machine the surface of the pad would be the best way to go to have the original calipers fitted to
my car.
This has all come about because I wanted to fit the standard steel wheels onto my GT and although I haven't got GT
wheel covers to fit I have PR20 Deluxe covers (courtesy of Farmer) to go on.

For those who are interested. The DB704 have a rectangular backing with a round pad with the slot for the pin and
has a single mount at the centre top. Pendulum style. The DB52 pads are rectangle backing and pad and with a mount
point at the top corners. Similar to Gemini T series and Mitsubishi's.
Chassis number change was 4202358. 1966.

Dave.

[Glenn]

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FDB Calliper Pistons

There are two callipers, the early DDB704 split calliper as per the 1964 and 1965 S1 and S2 Bellett GT and homologation disc brakes and the later FDB52 calliper as fitted to all Bellett GT from 1965 to 1973. The early callipers are the same as the E Type Jaguar rear callipers both body, pistons and seals. DDB704 47x54mm.

The later FDB52 cars use a 2 x piston x 57mm (2.25”) diameter Girlock P/N 64325438 which is the middle piston in Jaguar 3 spot callipers.
------------

Tom
Do you have a part number for the seals for the middle piston in Jaguar 3 spot calipers.
glenn

[Farmer]

I found a new set of 4 genuine caliper pistons on Yahoo auctions. They cost me $200, and the postage was about $100 through Jayce handling house. Absolute bargain I reckon. Another set was listed straight away, and were still there last time I looked.
Thankfully Dean supplied me with a set of seals a little while back.
Cheers, Matt.