Bay brake servo replacement?

[Bugsy_malone 666]

Ok so today I started on the mission of replacing my bay brake servo as it has bee suspect for a while, when I got it off it was full of all sorts of crap so no wonder it wasnt working!

Few weeks ago I had bought a couple of Servos of ebay, a golf mk3 and a seat toledo (I think) and while I think essentially the servo is the same, the input pins from the pedal differ. The seat one has just a ball on the end of the rod, thats about it! The golf mk3 was much more usable as it had a threaded section with a bit I could unscrew and mate to the screw adjuster thing on the original brake pedal rod.

Great news the mk3 golf cylinder bolts straight to a stock bus servo mount, its a little bit tight but its not like its going anywhere to rub! also I found that the Master cylinder mounts are the same, however I have come up with a problem.

The idea was to use my stock bay master cylinder as its only 3 years old and obviously designed to work with the system thats in place, a stock disc/drum setup and while the master cylinder bolts to the servo fine, the little rod inside that pushes against the M/C is about 1/2" to short!


So I was kind of wondering what I can do at this point?

I have seen people use golf M/C's and I do have a mk3 M/C but its the 2 outlet one which I beleive is only 20.64mm unlike the GTI/TDI/VR6 22.2mm ones (which is the same diameter as the bus) although as of yet I have been unable to find out if the strokes are the same/better than a bus.

Ideally I wanted to just use my good bus m/c however if theres something which is a perfect fit and is better thans not more than about £35 (mk3 golf ones are for example) then I am open to suggestions?

I did think of making a small 1/2" spacer type rod to fit into my M/C so I could just use that if it makes sense.

Any Ideas so I can finish this?
_________________
Second Gear All The Way Baby!

Doing Thing Differently.

[richbaker78]

dont panic - I have come against the same problem....and solved it.
I used a new polo servo as i needed a smaller servo - like the golf stuff it bolts to existing mount. BUt it has the ball thing on the push rod like your seat one - I chopped this off and cut a thread onto the push rod so i could bolt a push rod to it.

LIke you i wanted to run a specific MC (porsche one) whilst it bolted up the servo rod fell short of the MC cup - so i simply made a small spacer which fitted over the end of the push rod and was trapped against the MC - once its bolted up it goes nowhere.

Hope that helps.
R

[13 window deluxe]

i used a mk2 golf driver servo (m10 clevis pin) i did try a 16v gti and it was miles to big then a 8v gti which was close to fitting but fouled the handbrake cable so plumped for the driver item in the end along with a mk2 16v 22mm master cylinder as i was using disks front and rear and residual pressure valves are set lower on disks than drum using a drum brake master cylinder with disks would have caused brake bind. If i was you bugsy i would use a LATE mk2 16v 22m master cylinder along with beetle remote reservoir fittings to conect to original bay brake fluid reservoir under seat
_________________
1964 rat 13 window deluxe 1Z tdi,
1975 rhd twin slider tintop (TBA)
1991 golf 2 gti with tweaked AHU tdi,

previous tdi swaps: gone but not forgotten
1979 rhd twin slider tintop bay ahu 1.9tdi
1990 T25 1Z 1.9tdi
1993 suzuki samurai with 1Z 1.9tdi

[Bugsy_malone 666]

ok been doing a bit of research since my post and things have moved along a little.

Clutch/handbrake cables are a bit close to say the least! on my bay it has a little thing I unclipped from the servo that a cable runs in as its almost like its designed to rub the handbrake cable!

I did a bit of reading and I think the mk2 has an 8" servo, the mk3 its more like 9.25" although stock bay one is about 9" measuring roughly.

had a bit of a look on the ATE website as to what spec the master cylinder was I had and it wasnt clear at first, from what I gather I had bought a GTi servo/Master cylinder, acording to ATE the only ones that they listed for the car in the config of pipes and style I have means its from a GTi with ABS, 2 pipe outlets of 12mm rather than the usual 10, what wasnt clear initially was the actual piston diameter.

Did a bit of research and it would appear on the top of M/C there is a number stamped which will be 20, 22, 23 etc which refers to the piston size! mine happens to be 23 meaning its 23.81mm diameter, its the biggest they do I think which means I should be able to stop just fine!

The bit I am still looking at is the specs to do with piston stroke and also the diameter of things like the caliper pistons, luckily unlike new haynes the old manual ones have all the specs for the bay, so I am just looking online to see if I can find info for the golf.

Initially I was concerned because while I have a larger bore, the rear wheel cylinders on a golf are just 19mm at biggest while bus ones are 23.81! I want to check the calipers out too and it maybe that we have a perfect match!
_________________
Second Gear All The Way Baby!

Doing Thing Differently.

[13 window deluxe]

[Bugsy_malone 666]

ok well I'm still working through it here, the servo only just fits so I think 9"

been looking through what info I can find on the ATE website which is actually pretty useful with all the different parts, shame it doesnt include the stroke of the M/C!

original bus M/C =22.20mm
Golf M/C = 23.81mm

front golf calipers for the gti are 54mm pistons, campers both T2/T25 seem to have calipers with 54 mm pistons too!

on the golf rear calipers are 38mm piston calipers, rear wheel cylinders are 15.6/19mm depending on the model, with the van they are either 22.2mm or 23.81mm, which to me looks like they match the M/C on the earlier ones so will match the new M/C.

now the only thing left to find out is the stroke of the M/C from the golf and what boost factor the servo has (bus is 2.05 apparently)

I will need to buy 2x 3 way brake line blocks so I can screw the brake light pressure switches into (as they are connected to inividual parts of the system front/rear) and I will also need to make some small adaptor hoses with 12mm fittings one end and 10mm fittings the other end!

then it just going to be a case of looking at putting a resevoir in as the old bus one wont work with the new M/C! I know what you mean about using the bug pipe take offs though, I have some so we'll make something work!
_________________
Second Gear All The Way Baby!

Doing Thing Differently.

[famous phil]

Hi, I'm sure that I read somewhere that the t25 servo is the same fitments , because these are mounted behind the dash binnacle they often look new
_________________
Auto Union Munga Jeep ,T4 2.4td , T4 2.5tdi ,Mercedes S Class on LPG , 66 splity deluxe , GP mk1, 3 type 25s 1 with 1.9dt pug engine + 1 with N/A pug engine ,,there are 6 t25s with pug power in Darlington

[13 window deluxe]

[sburford]

on a semi related topic. has anyone any experience of adding a servo to a 68 bay. im right in thinking that they dont have one from the factory. i do have one off a mk1 golf gti, cold that be retrofitted?

[Bugsy_malone 666]

[13 window deluxe]

[13 window deluxe]