79 MGB GT rear brake cylinders & hub seal

[samgt79]

Hi all,

My first post, just got a couple of quick questions. Firstly I changed the rear hub oil seals today, the old seals sat flush but when putting in the new seals, one of them has sat further back, does this matter?

Secondly, I went to fit two new rear brake cylinders, but the new ones don't line up. On the old cylinders, the bleed nipple and little black pin were inline with each, on the new cylinders the little black pin sits higher than the bleed nipple and therefore won't fit through the backing plate. Any ideas? should i just file the backing plate to fit?


Many thanks in advance

[Geordie MGmike]

samgt79 said:

Firstly I changed the rear hub oil seals today, the old seals sat flush but when putting in the new seals, one of them has sat further back, does this matter?

Probably not as long as the seal is the same amount back all the way around. One possible issue could be if the half shaft has a little lip the seal may not seal correctly or may fail early.

samgt79 said:

Secondly, I went to fit two new rear brake cylinders, but the new ones don't line up. On the old cylinders, the bleed nipple and little black pin were inline with each, on the new cylinders the little black pin sits higher than the bleed nipple and therefore won't fit through the backing plate. Any ideas? should i just file the backing plate to fit?

Have you got the correct cyl's? They differ from GT and Roadster and have different pin positions.

[samgt79]

Geordie MGmike said:

samgt79 said:

Firstly I changed the rear hub oil seals today, the old seals sat flush but when putting in the new seals, one of them has sat further back, does this matter?

Probably not as long as the seal is the same amount back all the way around. One possible issue could be if the half shaft has a little lip the seal may not seal correctly or may fail early.

samgt79 said:

Secondly, I went to fit two new rear brake cylinders, but the new ones don't line up. On the old cylinders, the bleed nipple and little black pin were inline with each, on the new cylinders the little black pin sits higher than the bleed nipple and therefore won't fit through the backing plate. Any ideas? should i just file the backing plate to fit?

Have you got the correct cyl's? They differ from GT and Roadster and have different pin positions.

Hi Geordie,

thanks for your response, I ordered the cylinders using the reg but looking at some on the internet I think your right and they're the wrong ones, will order some replacements tomorrow.

thanks again

[Geordie MGmike]

samgt79 said:

I ordered the cylinders using the reg but looking at some on the internet I think your right and they're the wrong ones

Hmm interesting. Have you got the wrong axle for your car?
If the parts ordered by reg are correct for the model then the axle (or back plates) may have been changed to a one from the other model.

IIRC the roadster cyl's have a larger bore to prevent locking up under heavy braking as a result of the reduced rear end weight.

So the questions are; what model do you have and do you need to buy replacement cyl's or backplates?

[Geordie MGmike]

Of course there is also the other option.... It's a ringer
eg, a tax free GT reg on a newer roadster