Hydraulic to Vaccum servo conversion

[diesel des]

Good man its ordered too. In for a penny. .... If I'm really stuck I will pull the servo and master cylinder from a c4 tdi but I think a fuel hose will need removed and remade to fit the urs by the look of things. Also maybe the master cylinder is less capable on the tdi??

[macspring]

Haven't seen the TDi installation - obviously, :roll eyes: Would the master cylinders' fitting pattern not be the same, making them interchangeable ? Just suggestin...........

[diesel des]

These new servos have a different master cylinder bolting arrangements so they won't fit an old servo. The new master cylinders also have a different thread for the brake pipes so I have had to modify my brake pipes.

So I mould need to change my brake pipes again to use the tdi setup. Maybe the urs master cylinder would fit the tdi servo. Need to check that.

[popdemonic]

A friend of mine installed 1 1/2 diaphragm booster from 2001.5 Passat Tdi on his UrS6.everything is almost bolt right up.IIRC on the C4 firewall,
there's 4 lugs but you could be mounting the Tdi booster with 2 bolts diagonally.i will be finding some photos later.

[diesel des]

Great thanks for the feedback. Pictured would be great!

[Error404]

I checked Elsa, there is zero info about pre-loading the servo pushrod.
It just clips into the back of the brake pedal and that is that. There is a bit about setting the pushrod length, same as our hydro servos but that is it.
It also states that on the petrol manual engine cars the vacuum is generated from the inlet manifold, the vacuum pump only runs at start-up and if manifold vacuum rises above around 500mbar. Auto cars the vac pump runs more regularly at idle with foot on the gas etc.
So it seems like there is something amiss with us not being able to generate proper vacuum
It will be interesting to inspect our new RS6 servos....

[diesel des]

Maybe these servos die when they have been sitting on a shelf for a while. Really weird. But at least yours is doing the same as mine and I haven't gone mad. I tried the suck test on a tdi one installed on a tdi parts car and it holds vacume fine and has been sitting on the car for years no working...

[Error404]

Very odd indeed.
When I get back from my travels next week I'm going to pull the vac line off my stock B3/4 servo and test the the D3 unit and the new RS6 one.

[diesel des]

With any luck I should have tested the rs6 one over the weekend. Cheers des. P's have a good holiday.

[Error404]

I await your results

[Chris5044]

Hey guys Had the car checked in at the garage for a once over. There is a list of things to replace. (general wear and tear).
One of the parts is the "Brake Booster sphere".
Now am i right in thinking that we are talking about this same item here? Also the word "bomb" is this the same device?.
If they are problematic, then is it worth converting it to this vaccum setup?

[Horsty]

the "bomb" is the hydraulic expansion thing below the brake booster.
its located more closely to the front subframe.

vacuum stuff is way cheaper and in my opinion even better.

[Chris5044]

Hey thank you Horsty!
Though does anyone know what part the garage means?
He says when you pump the brakes the brakes have assistance in one pump but after that you lose this with the rest of the pumps.

What part would I need to replace? -- would it be wise to then switch instantly to vacuum?

[jade]

Hey thank you Horsty!
Though does anyone know what part the garage means?
He says when you pump the brakes the brakes have assistance in one pump but after that you lose this with the rest of the pumps.

What part would I need to replace? -- would it be wise to then switch instantly to vacuum?

Yes he is referring to the bomb

[Chris5044]

Hey Thank you very much Jade! ... hmmmm.. ok vacuum it is then...