Brake servos - what’s the difference?

[Tr4aJim]

Folks, I’ve been looking at installing a brake servo to my TR4A (LHD). Moss US only offers an “aftermarket” kit for $180. However Moss UK sells two kits: an “aftermarket” kit for £99 (which looks identical to the Moss US kit), and a Lockheed kit for £291. The TR Shop sells a kit for £95, which from the picture appears to be similar to the other “aftermarket” kits.

Any opinions/experiences with the “aftermarket” servos or the Lockheed servo? There must be some reason the Lockheed kit it more expensive, but is it worth the extra £200?

Thanks

Jim

[r-fox]

Since 2010 braking by such an aftermarket kit using silicon fluid.

Do not use my TR4 in wintertime.

No problems, no complaint .

Wolfgang

[Andy Moltu]

The Lockheed item is a quality item. However they seem to be sporadic in terms of availability.

The after market generic ones are a bit hit and miss I  terms of longevity/quality. They seem to be the same universal kits with all the brackets and pipework. If you for the cheaper one you might as well get it for far less on Ebay. 

[trchris]

Agree with Andy the cheaper kits are known for bad quality sometimes second-hand Lockheed/Girling units become available that can be overhauled if necessary 

Chris  

[Chris Hubball]

I have a Moss aftermarket servo fitted using silico fluid in my TR4 no problems so far.

Cheers Chris

[Tr4aJim]

Thanks everyone. I guess I have some coin-flipping to do.

Jim

[Malbaby]

You probably do not want to.....consider installing a neat TR6 system.

[ianc]

Better still - don't bother with a servo.

Ian Cornish

[John Morrison]

12 minutes ago, ianc said:

Better still - don't bother with a servo.

Ian Cornish

+1 just something else to go wrong.

John

[Tr4aJim]

Well the knees are starting to get cranky if I put pressure on them in a certain way (interestingly they don’t bother me going up stairs, but they complain going down stairs). Lately, if I hold the brake for longer then a few seconds the knee starts to protest. Luckily the gas and clutch don’t need much force and are not an issue.

I thought about going the TR6 (or 250) route but that appears to need a lot of careful fabrication on LHD cars due to the proximity of the steering column.

Its not a make/break issue yet, but the writing is on the wall.

Jim

[RogerH]

Hi Jim,

It is so easy and inexpensive to fit a servo just do it and see if it does  the job.

 

Roger

[Andy Moltu]

Exactly- it’s a bolt on item and if you don’t like it remove it.

My bet is you will keep it.

Fitting the TR6 item may be tricky because of the throttle linkage and plumbing in the dual circuit bakes. A significantly bigger job and vastly more expensive when you consider the parts of required.

[John Morrison]

21 hours ago, Tr4aJim said:

Well the knees are starting to get cranky if I put pressure on them in a certain way (interestingly they don’t bother me going up stairs, but they complain going down stairs). Lately, if I hold the brake for longer then a few seconds the knee starts to protest. Luckily the gas and clutch don’t need much force and are not an issue.

I thought about going the TR6 (or 250) route but that appears to need a lot of careful fabrication on LHD cars due to the proximity of the steering column.

Its not a make/break issue yet, but the writing is on the wall.

Jim

Jim 

that is the only situation that would make me consider fitting a servo.

That said recently fitted one of the under £100 generic ones bought from the internet to a fellow group members Jensen 541, (Original Clayton  De Wandre Servo, being both very costly and time consuming to have repaired) without issue.

A simple straitforward plumbing job, and is working as it should.

To try and answer your original question, I wouldn't hesitate to have one of these on my TR, when the need arises.

John.

[Tr4aJim]

Thanks again everyone! Looks like fitting a “replacement” unit will be this winter’s project. 

Jim

[Malbaby]

Another consideration is the diaphragm size of the servo, and if single or twin.

[Andy Moltu]

Single is fine.

The discussion on the 6 forums about fitting dual diaphragm/Volvo servos perhaps reflects the limited vacuum that some of their cams develop and the restrictions in size fitting it where it is on the PI cars.

The kits for the 4 pots seem pretty similar and give adequate assistance. The same kit seems to be sold for Morris Minors and MGBs.

[Tr4aJim]

One more question. The PO removed the stock PCV system, capped the port on the inlet manifold, and installed a TR4 breather tube in the block (fine by me as I’ve had no oil issues). Is that PCV port on the manifold suitable as the vacuum source for a booster?

Jim

[stuart]

23 minutes ago, Tr4aJim said:

One more question. The PO removed the stock PCV system, capped the port on the inlet manifold, and installed a TR4 breather tube in the block (fine by me as I’ve had no oil issues). Is that PCV port on the manifold suitable as the vacuum source for a booster?

Jim

Yes that will work fine for the servo.

Stuart.