Advice on buying a new brake master cylinder

Post by **ET_in_black** » Wed Dec 09, 2009 6:32 am

Hi All,
I need to buy a new late (13/16) brake master cylinder.
Looking around on the internet I can see that the major suppliers offer "original Lockheed". I've also seen 2 other types with part numbers DELPHI LM15453 or GMC115 at slightly cheaper prices.
Has anyone got any recent experience of buying any of these, or any recommendation which I should get?
One other question which might influence this: I've got disc brakes, so I will need to remove the "tophat" seal: does anyone know if I can buy one with this seal already removed?
Thanks,
Ed.

Post by **LouiseM** » Wed Dec 09, 2009 7:37 am

There's a thread here with regards to buying lockheed or 'pattern' cylinders. Personally I would go for the Lockheed as there have been some problems with 'pattern' ones.

http://www.morrisminoroc.co.uk/index.ph ... t=lockheed

Yes, you would need to remove the 'top hat' if you have disc brakes and as far as I am aware you can't get cylinders with these already removed.

Wed Dec 09, 2009 10:57 am

removing the top hat is easy..

If you are confident enough in your ability to replace a brake cylinder removing the top hat is easy, the most difficult thing to do is to remember to remove it before you have tightened everything up..

Post by **M25VAN** » Wed Dec 09, 2009 9:31 pm

I fitted a Delphi LM15453 2 or 3 years ago with no problem, including removing the top hat seal. It was bought as a Lockheed BMC, I think Delphi and Lockheed are one and the same now.

Post by **ET_in_black** » Sat Dec 12, 2009 1:34 am

Hi folks,

Thanks for the feedback. In the end I went for a new Lockheed master cylinder from one of the main suppliers.
Next job is to remove the "top hat" seal. So, sorry if I'm going over old ground, but can I check exactly which seal is the "top hat" one?
I'm looking at the diagram of the brake master cylinder on page 122 of the Haynes manual. Are we talking about the "valve cup" which is normally fitted inside the "valve body"? Is it this valve cup which needs to be removed?

Thanks,
Ed.

Post by **rayofleamington** » Sat Dec 12, 2009 2:51 pm

Lockheed don't really exist anymore, and parts manufactured as 'original Lockheed' are not (unless it is 20 year old stock - which for brake cylinders you wouldn't want!).
The original parts were produced in the AP factory on Tachbrook Road Leamington Spa. That part of the AP business no longer exists. Some of AP hydraulics business went to Italy and the small remainder of AP in Leamington was bought out by a Chinese firm about 7 years ago.
Delphi distribution was already selling AP parts (Lockheed and Borg&Beck) and they bought up varous AP trading names and now distribute their own parts with those logos. The parts distributed by Delphi are often to the original design, but that is not guaranteed.

For master cylinders, I'd be tempted to be as safe a possible, and there were problems with pattern parts (not that all 'genuine' parts were good either!). For wheel cylinders I opned up a pattern rear and a 'genuine' rear only to find the genuine one no longer had the original style cup seal so they were bth the same inside.

Back to he last question - for disks you want to remove the'cup' shaped seal thatn sits by the outlet (there is only one cup shaped seal)

Post by **ET_in_black** » Sat Dec 12, 2009 3:25 pm

Thanks for the reply Ray.
So, just to confirm: I'm looking at page 123 of the Haynes manual, and you mean part number 16 - right?

Post by **rayofleamington** » Sat Dec 12, 2009 8:19 pm

So, just to confirm: I'm looking at page 123 of the Haynes manual, and you mean part number 16 - right?

sorry, my dusty old Haynes manuals are miles away, but hopefully someone will confirm. All the other seals are 'rings' (i.e. with a hole in the middle)