tr7triumph.com

Hi All,

I know there are Sherpa upgrades available but I initially want to obtain a front seal for my standard Tr7 Servo.

The Girling web site seems broken does anyone know the part no of the servo please.

Check out Bigg Red they do all the seal and rebuild kits, also pistons/seals for caliper rebuilds.

https://www.biggred.co.uk/

Got my rebuild kit for my TR8 servo from them

Thanks Russ. How did you manage to twist the back off?
Alan

Might have misunderstood, I didn't take the drum apart, just the master cylinder part.
I do have the standard TR7 unit I took off if you want it?
Based in Gloucestershire

Hi Alan, I have a copy of an old Lockheed catalogue that lists the servo for the TR7:
Servo part number: SSB80018
Repair kit part number: SSB80019
Servo and Master Cylinder assembly part number: 4258-291
Non return valve RHD part number: 4315-063

Not sure if Girling servos were used on the TR7.

Hope that helps,
Rich.

Some years back, a club member needed a servo drum for a TR7 and couldn't find one but had a TR6 one that he used (brought the disassembled TR7 one to a meeting to show what it looked like inside on case any one was going to rebuild one in the future), internal spring forcing two halves apart, have to be aware when separating. It had to be turned 90 degrees to fit the mounting bolts, don't recall any other special adaptations off hand. Apparently it is slightly larger and gives more boost.

Hi Russ, Thanks for your offer. I do have a spare to replace the original. someone had snapped one of the 4 the studs that has the dash support bar so the bulkhead was flexing.

Hi Rich, Many thanks for digging that out. I was going to twist the back off and weld in a replacement stud (OK with my welding it probably wouldn't have worked) but it seems very tight.

Alan

I did try to tap the base plate around by 90 degrees but it wouldn't move. there were some amusing solutions from Asia on You tube (bending the tabs out then hammering them in again) but I didn't fancy trying that. Even if you could get it to vacuum seal the servo was very butchered. A US chap used a long flat bar with holes for his E-type servo studs which seemed to work (push down and twist).

Yes, there is an internal spring that is forcing them apart (which will happen when released so safety provisions need to be made for that). Between that (inducing friction) and any oxiding that may have happened, some vibration (banging) may well be needed. Some compression, relieving some of that spring pressure as well. An engineering problem requiring use of your ingenuity. Of course with anything like this, some will be easier to take apart than others.

Many years ago I took one apart attempting to resolve a problem. (not on a TR7)
Within days a replacement was found and any repair soon forgotten and it has been on the rack ever since
These pics may help.
Getting it apart was a two hander with various clamps and devices to keep it all safe and doable. The two halves were marked before turning- it separates when the crescent shaped detents around the edge all line up but the big internal spring and rubber gasket fight you,-care when separating is needed.
As well as the crescent shaped detents there are three cut-outs that align with three `tabs`(on this one) that you need to watch out for. Careful scrutiny before turning will tell you which way to turn as the tabs are a form of back-stop when re-assembled
Do mark the two halves as it`s a puzzle to work out which tab meets its correct cut-out after the event!
Hope this helps.

Final pic, just an offering up without the spring inside!!!- the 4-bolt face would need a clockwise turn of about an inch to lock in place and re-align the marks (black lines)

Thanks Howard.