Early 2000TC Lockheed Servo

#1
My car is an early car with Dunlop brakes and instead of the proper Lockheed servo, it came to me with a "PowerTune" knockoff version of a Lockheed servo. This was discussed in this thread when I purchased my car. The brake feel is still quite notchy, almost as if the piston sticks in the cylinder, then releases suddenly,, making it hard to smoothly modulate the brakes. It's really noticable when I switch from the Rover to my Daimler V8-250, which has nice, smooth brakes after a servo rebuild.

Given the horrible reviews I have seen of the PowerTune units, along with the fact that the unit had to be rotated to mount properly, I have decided to replace it with a proper Lockheed. My initial thought was to source a used unit and send it to Power Brake Exchange, as they have rebuilt other servos for me. However, this morning I received an e-mail from SNG Barratt with a link to this video for what is supposed to be a new Lockheed servo. At $175, it's cheaper than a rebuild, and it does look to be a decent quality part.

I'm curious if anyone can say if this unit has the proper assist ratio, as I am worried that extra boost will make the brakes feel a bit numb, or perhaps too touchy.

Thoughts?

Tom

 
#2
I may have answered my own question, but then again, it's not 100% clear:

This document from Moss lists the LR18230 as the proper unit for a Rover 2000 and 2200, but only from Chassis suffix "C", and my car is an "A" suffix car. Given that literally everything in the braking system changed between suffix "A" and suffix "C", confirmation would still be nice.

While looking for details online, I did stumble across the FIA homologation paperwork for the 2000 TC, which was pretty neat. It lists the 5,000th car as having been produced October 25, 1966, exactly five months after my car was built (to the day!). I wonder when production started?
 
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Ban306

Active Member
#3
The Youtube clip was posted on the 1 Oct 2019 and already has one thumbs down and no reviews.
I am no expert on this subject and defiantly do not claim to be one.
It sounds amazing better breaks ect and less expensive price,
I would personally use a Trusted Rover P6 seller like Mark Gray or Wins International
It might be more money, it might be a rebuild, but I know what I am getting and that
the re-built unit would be A1
However I am not saying that SNG Servos are no good so I cant say either way sorry.
 
#4
@Ban306: I'm all for buying from folks who support the Rover community, and may very well if I go down this road and have the option. The servo in question is a Delphi/Lockheed part, so I imagine it's available from vendors other than SNG Barratt. Having said that, SNG Barrat USA is a half-hour's drive from me, so I can avoid the costs of shipping from the UK.

More than anything, I was just hoping that someone might know what unit would have originally been fitted to a Dunlop-equipped car, as there seems to be as much lore in that arena as there is fact. The LR18230 is a 4.25:1 unit, and if the original unit wasn't the same ratio, I'd rather have an original rebuilt.
 

Ban306

Active Member
#5
Hi Tom, its very early in the morning here in the UK but I am sure later on someone can give you far better advice,
sorry its not my field sdibbers or Demetris are the ones to speak to nothing they don't know about a P6 ;)
many others on this forum as well Good Luck with it :)
 

Demetris

Well-Known Member
#6
It seems that a Lockheed type 7 brake servo replaced the Dunlop unit for the 1966 model year cars (Oct 1965 to Sept 1966), while these still retained the rest of the Dunlop system.
The Dunlop type brake master cylinder was replaced by a Girling one in May 1966, and finally the rest of the brake system changed from Dunlop to Girling for the 1967 model year cars (Oct 1966 to Sept 1967).
All these are according to James Taylor.
 
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Demetris

Well-Known Member
#8
It is worth getting hold of J. Taylor's book about the Rover P6. It could be handy in many cases regarding required information about these cars.
 
#9
The 18320 servo is the correct one for the car, all single circuit Lockheed servos on the P6 are the same (5/8" hydraulic bore, 3/8" reaction valve bore, 4.25:1 ratio).

The Power tune units tend to either 3:1 or 1.9:1 units.

Yours
Vern
 
#10
Thanks again, Demetris, and thank you, Vern. I think I might take a chance on this servo from Barratt, just because they are close to me, and returns to UK vendors if something goes wrong could be tricky. I did get to the car and the parts list, so here are the relevant pages (168 and 169). You can't really make it out, but the previous (original) owner has marked "Mine - 2 Studs" next to item #45 in the parts list.
 

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#11
The two stud reference is about the number of mounting studs on the back of the servo. The single circuit installation servo had two studs and included a steady on the nose of the servo. When Rover introduced the NADA two servo dual circuit system, they couldn't include the nose steady, so the servos ended up with three studs. Single circuit cars then also got the new three stud servo, with the addition of a plastic cover for the unused third stud.

Yours
Vern
 
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#12
Also note that these servos are not an exact match for the original, the way the front & back shells of the vacuum chamber are attached together changed from a rotating lock arrangement to a clamping band. You could always swap those out for the original chamber if you wanted to be authentic.

Yours
Vern
 
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