Series 2A /3 LW brake servo

Hi, I'm after a brake servo off a long wheel base series 2a /3 I'm located in Northants.... cheers

Watch out for the dia, there are 3 sizes. A small one (useless) a medium one (most common, ok) and a large one (rare as hens teeth, if you find any I want one too)

Larger one is freely available here http://www.heystee-automotive.com/webstore/index.php?route=product/product&path=64_65&product_id=69

Not a cheap option and when I looked at it I wasn't convinced it wouldn't foul the steering box. Should give close on double the assistance of the 6" standard servo.

Just had a look, mine has a 7" servo that is a series servo. its a 2A with an S3 pedal box. I think the 6" is the "small" and well worth changing, the 7" that I have is OK but there does seem to be just enough room for the 8". The 8" wuold give me an extra 30% assistence (1:1.3) over the 7" for £200 so its a case of thinking about that. The limit looks to be the clutch pedal box, the wing is close but can be bent a bit.
Thanks for the Heystee link, they were out of stock for ages.

As far as i can tell while there were 2 different part number servos fitted to the Series 3 they were both referred to as 6" servos, apart from the Santana one I've never seen a 3rd which is larger.

Clearly when I measure the diameter of my 6" servo its largest dimension is significantly greater than 6" probably closer to 7". I assume that the diameter refers to the diaphragm size not the physical size. I also have an 8" servo which I haven't yet fitted and that measures 8" in outside diameter, whats going on there.

It seems that the sizing may be a little bit arbitrary, maybe the answer is a suitable tandem servo that keeps the diameter down.

Citizen Kane said:

Larger one is freely available here http://www.heystee-automotive.com/webstore/index.php?route=product/product&path=64_65&product_id=69

Not a cheap option and when I looked at it I wasn't convinced it wouldn't foul the steering box. Should give close on double the assistance of the 6" standard servo.

Click to expand...

Think heystee also point you in the direction of a Defender servo aswell which is the way I mite go when I get round to fitting a heystee disc conversion

I measured mine at the outside of the cylinder part, its just over 7" and is (I believe) the larger of the std series servos. Its probably just under 8" od over the flange so i would say the diapharm is 7". The Heystee one is an 8" diapharm and looks to be about 8 3/4 od which looking at mine would just fit between the steering box and wing but would need the clutch pedal reservoir bracket reversed to get clearance. The "small" servo looks like its a 6" diaphram and about 7" od. I've not measured one but I had driven with one and the brakes were pretty poor, the 7" is a lot better and I supect the 8" better again. The 8" Defender looks like a good option as its just a matter of sqeezing the rod end, thanks for reminding me thats possible, a lot cheaper than the Heystee.

The Type 50 Defender pedal box and servo inst a straight forward bolt in job. You may have clearance issues with the bonnet and you will definitely need wing cuts. The pedal box locates the servo both higher and further forward. I started to make mods to one of these to ensure I had bonnet clearance but it soon became apparent that even though I already have a Series 3 with a servo clearance cut in the wing this area would need further mods and maybe mud shield mods to allow for clearance if you have a tandem master cylinder.

The Type 50 servo has a different bolt pattern so even if you mod the clevis fork it wont bolt to a series pedal box, its easy to make an adapter plate or weld on the tabs to the series pedal box. The Type 50 8" servo measures 8" diameter.