Sherpa Brake servo for Tr7

[UKPhilTR7]

I have just seen this servo unit on ebay -

http://www.ebay.co.uk/itm/TRIUMPH-TR7-TR8-MK2-TRANSIT-SHERPA-SERVO-UNIT-COMPLETE-BRAND-NEW-NOS-/381761977577?hash=item58e2c97ce9:g:QPMAAOSwYH5WCCuk

Is this the uprated one that we can add to our tr's to help improve the breaking?

[Spike]

Yes.

I bought one (I think from the same seller) a couple of months ago and have just recently fitted it. Simple nut and bolt job and then bleed the brakes.

You'll need to swap over the brake pressure switch, as the new one has a different connector. Just unscrews.
When you disconnect the peddle don't pull it towards you, you'll end up bending the brake light switch bracket.
I'm going to check to see if you can swap the reservoirs over, the new one is a flat top so you end up with a bubble of air in the top.
Peddle sits ever so slightly higher, the rod is about 3 to 4mm longer. I've not really noticed the difference.

I'd had uprated brakes on the front (old Rimmer kit) and these made the world of difference.

regards

Graham

[REPLIC8]

I do find it slightly frustrating when you're watching something on fleabay and then it gets posted on a forum. It just means more people to bid against who may not have known it was there.

[Spike]

These seem to come up quite frequently, from mini spares places for some reason. If it hadn't been for somebody on this forum pointing one out to me I'd never have got mine.

As I said they seem to come up quite often so just keep an eye out, or set up an alert.

[sonscar]

I understood that a servo does not improve the brake efficiency,it just makes it easier to press.Or am I wrong?.Steve.

[FI Spyder]

I have locked up all four wheels on newer tires, how much more brake efficiency do you need? True this is panic stops (why else would you lock up wheels) and as pointed out it's the modulation a high brake pressure that is lacking. Do the uprated servos improve the modulation at the higher end of braking?

[UKPhilTR7]

Thanks for that Graham, it is great to know that it is the o e. With three days to go,it is still a good price.

I personally feel that people pointing out things like this is good. It will show more demand and then hopefully the sellers will get more into the market. The nature of an auction is you never know what it will go for in the end.

[Stag76]

The problem with the TR7 braking is not down to the booster, but the size of the front discs.
Brakes operate by turning kinetic energy into heat, and as the discs get hotter, the ability
to convert to heat is reduced until it reaches the "Brake Fade" stage. There is not enough surface
area or volume to dissipate the heat generated in the 9mm solid discs.
A bigger booster will increase the clamping pressure, which will improve the braking, but,
at the same time, heat the discs up quicker, so fade will happen sooner. Different combinations of
pads etc. have the same effect.
The existing booster is capable of servicing a lot bigger discs and calipers, up to the stage where
it cannot supply the fluid transfer required. Rodney Wells on this forum used the standard booster
with holden 2-pot calipers and Subaru WRX discs to good effect on his 4.0 litre Toyota powered TR7.

The only real solution is to increase the size of the front discs, pads and calipers.

[Spike]

The listed brake servo and master cylinder will give you more clamping force. On a standard set-up with good quality disks, pads etc... it will not make a huge amount of difference.

If you've fitted a 4pot conversion I'd recommend the upgraded master cylinder as it moves more brake fluid for the same movement (bigger bore), otherwise you'll feel like you're pushing the peddle through the floor.

[saabfast]

I fitted an uprated servo/master cylinder to mine, not particularly for extra braking as I had found the original satisfactory and could lock all four wheels if trodden on hard, but on trying to rebuild I found the auxiliary shaft was frozen in. I tried a recon unit which leaked. S&S advised most do and suggested the new uprated unit. I thought it was a Sherpa unit but it was a straight servo and master cylinder unlike the one in the ebay ad which seems to have a tube running from one port to a block on the drum. Everything on mine was a relatively straight swap including the wedge reservoir which fitted straight in. It all works fine but, as it was some years ago, I can't remember if it felt a significant improvement on the original.

[Spike]

The pipe that's already fitted goes to a small block which is some sort of splitter. Just unbolt and remove it. The fitting after is just nut and bolt job then.

[Spike]

The question we all want to know is did you get it? Seems it went for quite a reasonable price (40 quid less than I paid for mine anyway)

[busheytrader]

Hi, I bought the "uprated" TR8 master cylinder & servo combo from Rimmer Bros when it was included in one of their winter discount sales a few years ago.

Until then, I'd never felt comfortable with the increased brake pedal travel after I'd installed my Ford Capri 2.8i discs and calipers. The retardation was great but the pedal moved far too much for comfort. The swept volume of the standard master brake cylinder and the greater swept volume of the larger callipers = increased brake pedal travel.

The larger servo does provide extra power assistance to the pedal but IMHO my wedge needs the larger TR8 master cylinder to push more fluid into the larger callipers to reduce pedal travel. The pedal travels far less now giving more feel and confidence. Fitting braided stainless / Teflon hoses reduces this even more.

Adam