-
Hi Guest!
If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
There are some perks with a member upgrade!**Upgrade Now**
(PS: Subscribers don't see this gawd-aweful banner
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
bugeye master cylinder
- Thread starter rossco
- Start date
Share this page
twas_brillig
Jedi Knight
Offline
There are two outfits that do rebuilds that I'm aware of: Sierra Specialty and Apple Hydraulics. I had some form of weird rebuild (a 'Roadstar') in our BE, and both shops were familiar with it. I went with Sierra, but no particular reason either way.
https://www.brakecylinder.com/spridgetbrakes.htm
https://www.applehydraulics.com/brakes.htm
Doug
https://www.brakecylinder.com/spridgetbrakes.htm
https://www.applehydraulics.com/brakes.htm
Doug
dklawson
Yoda
Offline
Jack, I got my unsolicited British Motoring "magazine" from Moss today. I noticed they are now offering the tandem early Spridget master cylinders for closer to $210. I don't know if that's the same one used in a BE but it sure sounded like a better price than I last remember seeing. Anyway, it may be worth checking Moss' current prices before discussing rebuilds with Sierra or Apple.
Mike, even the new TRW/Lucas/Girling (whoever's name is on the box) master cylinders all seem to say "no DOT-5". I inquired about this and was informed that it wasn't a rubber compatibility issue so much as it was a "lubricity" issue where the DOT-5 fluid was thought by the manufacturers to not offer the correct lubricating qualities for the surface finish in the bores. I have DOT-5 in all my LBCs and no failures yet. I'm just passing along what the TRW folks said about DOT-5 in their products. It may be the same reason the rebuilders/sleevers don't want people to use DOT-5.
Mike, even the new TRW/Lucas/Girling (whoever's name is on the box) master cylinders all seem to say "no DOT-5". I inquired about this and was informed that it wasn't a rubber compatibility issue so much as it was a "lubricity" issue where the DOT-5 fluid was thought by the manufacturers to not offer the correct lubricating qualities for the surface finish in the bores. I have DOT-5 in all my LBCs and no failures yet. I'm just passing along what the TRW folks said about DOT-5 in their products. It may be the same reason the rebuilders/sleevers don't want people to use DOT-5.
G
Guest
Guest
Guest
Offline
I've seen them new on ebay for around $200 as well.
scoutll
Jedi Knight
Offline
Doug,
1098 Spridgets are not the same as the earlier Bugeye and 948 Sridgets. The earlier cars used a 7/8" bore brake cylinder and the later disc brake ones used a 3/4" bore cylinder. The big stores and most of the ebay sellers pass off the 7/8" MC for everything up to the dual system cars. They will work, but apparantly, there is a definate difference in braking on the later cars.
Only a couple of vendors on ebay acually sell the 3/4" unit and it was pricy last time I checked.
1098 Spridgets are not the same as the earlier Bugeye and 948 Sridgets. The earlier cars used a 7/8" bore brake cylinder and the later disc brake ones used a 3/4" bore cylinder. The big stores and most of the ebay sellers pass off the 7/8" MC for everything up to the dual system cars. They will work, but apparantly, there is a definate difference in braking on the later cars.
Only a couple of vendors on ebay acually sell the 3/4" unit and it was pricy last time I checked.
dklawson
Yoda
Offline
Thanks for the information Bryan.
I checked the Moss publication again when I got home. The Moss part I mentioned above is their item 180-671 listed as a dual MC for 948 drum brake Sprites for $210. The magazine add did not list the bore size but the Moss web site does say it is 7/8" as you mentioned above. Still, based on the application and your comments above, would this not be the correct MC for Rossco (the original poster)?
I checked the Moss publication again when I got home. The Moss part I mentioned above is their item 180-671 listed as a dual MC for 948 drum brake Sprites for $210. The magazine add did not list the bore size but the Moss web site does say it is 7/8" as you mentioned above. Still, based on the application and your comments above, would this not be the correct MC for Rossco (the original poster)?
twas_brillig
Jedi Knight
Offline
Have a look at the two web-sites as there's discussions on the Sierra one for sure about bore diameters. When we had ours done, I asked for a change in the clutch bore to match the Datsun 5 speed we're (still) installing. The next rebuild will need non-original BE bores to match the later disc/drum brakes plus a Datsun 5 speed.
Doug
Doug
64rocksprite
Jedi Trainee
Offline
Doug,
So you're going to a 3/4" clutch for the 5-speed? I understand the reasoning for the 3/4" on the disc brakes, but this is the first I have heard of the 7/8" being an issue for the clutch..crud. I have a 7/8" MC I was planning to use with rivergate's slave..
So you're going to a 3/4" clutch for the 5-speed? I understand the reasoning for the 3/4" on the disc brakes, but this is the first I have heard of the 7/8" being an issue for the clutch..crud. I have a 7/8" MC I was planning to use with rivergate's slave..
Trevor Jessie
Yoda
Offline
Devin, I think that will work.
Check out gerhards garage (gerhardsgarage.com)for a lengthy write-up on the dual bore master cylinders. He teamed up with sierra to remanufacture 3/4" pistons to put in re-sleeved master cylinder bodies for the disk brake conversion. I went to his place and checked the operation out once when I was in San Fran. Quite impressive undertaking! Gerhard is a great guy and would love to talk to you about this spridget brake master cylinder dilema!
Regards
Mark
Regards
Mark
twas_brillig
Jedi Knight
Offline
We kept the original 7/8" bore for the drum brakes, but went with 3/4" bore for the clutch as we'd ordered the Rivergate slave cylinder and that's what they recommended. Since I wanted the master cylinder to be rebuilt anyway, changing the bore diameter wasn't a problem - I don't remember Rivergate's comments on retaining the 7/8" bore for use with their slave.
Doug
Doug
I'm having a problem with the m/c brake side bore. After bench bleeding, the piston would work fine, then the piston will bind in the bore and will not fully retract.
I just had the m/c sleeved by Sierra Speciality,(I know they do great work)so I'm sure they did the work properly.
H as anyone had this problem? I dis-assembled the brake side to look for foreign matter and found none. The only way to remove the piston is by a blast of low pressure air.
The only thing out of the ordinary was I switched from silicone brake fluid to Castrol GT LMA. I evacuated the silicone fluid by way of my power Mityvac bleeder.
I am finding small traces of silicone(small bubbles floating in the fluid). I thought maybe the seal on the piston was swelling but I was assured thats not the case.
Any thoughts please.
Thanks,
Ken
1960 Bugeye
I just had the m/c sleeved by Sierra Speciality,(I know they do great work)so I'm sure they did the work properly.
H as anyone had this problem? I dis-assembled the brake side to look for foreign matter and found none. The only way to remove the piston is by a blast of low pressure air.
The only thing out of the ordinary was I switched from silicone brake fluid to Castrol GT LMA. I evacuated the silicone fluid by way of my power Mityvac bleeder.
I am finding small traces of silicone(small bubbles floating in the fluid). I thought maybe the seal on the piston was swelling but I was assured thats not the case.
Any thoughts please.
Thanks,
Ken
1960 Bugeye