Thread: Part number for brake master cylinder 1950

Originally Posted by Lotz-A-Landies

My guess it's because they rust if the master cyl gets water in or sits with air in the cyl for a long time. They aren't part of the service kit, so get left out.

Diana

It's a worry because it must be there for a reason.. It has little bumps on it that keeps the rubber ring away from the face of the housing. It was included in the Girling brand kit I got , but as you pointed out , other after market kits don't include it.

The cylinder does function without it, but how it affects the dynamics or performance of the thing.. I don't know.

BTW its a bugger removing the large end plug after 50 years of solid compression. You need the correct socket , A good strong vice and a length of pipe for leverage. With old cylinders , the rubber cups tend to expand and become limp , loose their stiffness, fliuid then leaks around them.

Mike

Originally Posted by series1buff

It's a worry because it must be there for a reason.. It has little bumps on it that keeps the rubber ring away from the face of the housing. It was included in the Girling brand kit I got , but as you pointed out , other after market kits don't include it.

The cylinder does function without it, but how it affects the dynamics or performance of the thing.. I don't know.

BTW its a bugger removing the large end plug after 50 years of solid compression. You need the correct socket , A good strong vice and a length of pipe for leverage. With old cylinders , the rubber cups tend to expand and become limp , loose their stiffness, fliuid then leaks around them.

Mike

It looks to be a wave washer - most manuals I have read even prescribe which way round to fit it, and it is important, but I can't remember why.

The big nut will shift with some serious heat on it, but it is important to heat the cylinder evenly as well and NOT to quench it in water as it may crack,

Cheers Charlie

Originally Posted by Numpty's Missus

So.....if the kit is the same, is the actual master cylinder the same?

The SI uses a different size steel brake line to the SII/SIIA. I think the SII/SIIA is 1/4, and the SI is 5/16. This means that the fittings are tapped one size bigger in the SI unit.

It will be seen on the SII/SIIA unit that the line from the reservior to the master cylinder is one size bigger than the line from the master cylinder to the brakes. This larger size is the size that the entire SI is made from.

From what I have found, the SI uses the same slaves as the SII/SIIA, except that the thread for the flexible line on the SI is one size bigger.

I believe that the SII/SIIA vehicles used 1/4 instead of 5/16 steel line, as it is easier to remove the air from the smaller diameter line. In the larger diameter line, the fluid tends to go around the air, and not drag the air with it.

In theory, it would be possible to fit a SI with SII/SIIA slaves and 1/4 steel line, while maintaining the original master cylinder. A reducing adapter would need to be at the master cylinder to suit the smaller diameter steel line. Alternatively, a special flare nut could be sourced, which had the centre drilled to take the smaller steel line, while having the outside thread cut to the larger size. I would not do this though, as I would see this as cheating, and ovoiding some of the obscurities that constitute a Series I Land Rover. Much better to rebuild your original slaves and use all original size fittings.

SI slaves use special bleed nipples that have a thread that I could not source at any brake shop. It is BSF, whereas other versions are UNF. I sourced them from one of the after market dealers.

The flexible line on both SI and SII/SIIA slaves is UNF, just in different sizes.

Aaron.

hi Aaron

going to corowa next year / I maybe will be there.

The 80" used 1/4" brake pipes , this changed when the 86/107 came out in 1954 - they went over to 3/16" pipes ( thinner ) at that point in time , with a change to the brake hose connectors also. The pipe you refer to from fluid reservoir is 5/16" on a 80" .

4 wheel drives sell an adapter that allows you to use 2 2A front wheel cylinders on your 80" ... retaining the original hoses. It's a little tricky to fit as there isn't much room left when it is fitted.

The 80 hoses are a little difficult to find now . Dunsfolds have them .

The BSF bleed screws are a bloody pain : as are the stupid 4mm ball that is so easy to lose. BTW bearing retail companies sell those 4mm balls if you need some . The bleed screws are sometimes totally rusted in and you have to destroy them to get them out. heat /cool etc. The ball sometimes is stuck and won't seal correctly no matter how tight you do up the screw. The whole thing is a over engineered nightmare.. . there must be a modern replacement cylinder somewhere that would work. .

It looks like I got my sizes mixed up, but the point that I was trying to make was there were two sizes in use, with the earlier vehicles using the bigger size. It looks like that in my previous post, I need to substitute in 1/4 wherever I wrote 5/16, and substitute in 3/16 wherever I wrote 1/4.

I had no problem getting the flexible hoses for my 80". I went to my local (generic, not Land Rover specific) parts supplier, and they had them in the next day. If I need to order some for you let me know. They had the steel line and all of the associated fittings in stock.

All of my bleed screws were stuck in. I used vicegrips to get them out. This ruined them, but I had new ones to go in. I lost one of the small balls when I was bleeding the system. I had the bleed screw completely removed in an attempt to get it to initially gravity feed bleed. This wasn't working, so I pressed down on the pedal. Ping!! I never found the ball. I then put the new bleed screw in, without the ball, and it sealed well.

I would assume the place where I bought the bleed screws from would have more. Let me know if you need some.

Aaron.

talking of brakes :

The PBR part number for 80" brake hoses is H538 . But there would not be much of the PBR stock around now.. you would have to find a stash of old stock somewhere in an old PBR retailer... maybe thats what happened in Adelaide .. being the out of the way retreat it is !

Somebody here gave me a late 80" front axle with the wide spring saddles . The brake linings are fused onto the drums .. so the drums won't come off . It would have been sitting outside for 40 years maybe. The bleed screws on it look like a fuzzy lump of ferous oxide, hardy recognizable. I would like to salvage the tracta joints and other bits.. but how do I get the drums off ... heat maybe ?

Mike

Originally Posted by series1buff

.......... I would like to salvage the tracta joints and other bits.. but how do I get the drums off ... heat maybe ?

Mike

I would soak it in diesel for a couple of weeks first. That might work by itself, but followed by heat (careful of fires - let it drain!) should do.

Worth pointing out that if you unbolt the axle housing from the swivel, remove the nut on the end of the stub axle, and dissassemble the swivel housing, you should be able to remove the halfaxles and Tracta joints etc - and the swivel housing plus hub/brake will be easier to handle anyway.

John

PBR made the flexible hoses for me. They have the ends in stock.

I had to use a hydrolic puller to get my drums off, after using an impact driver to get the retaining screws off. One screw had to be "removed" by using a burr. If they won't come off, could you gas axe them off, then buy new drums?

My 80" still has it's hydrostatic braking system, with no adjusters or return springs. Has anybody else experienced this system?

Aaron.