Vacuum brake conversion in a UR

[DamoM]

Thought I'd give a quick run down as to how we got vacuum brakes into my ur.

We got the vacuum servo from a MK4 VW golf, the bolt pattern is the same as the Quattro. The push rod from the old unit had to be cut off and welded to the new servo

The master cylinder and reservoir is off the MK4 golf

The high pressure hose from the power steering to the rack needed to be made to bypass the hydraulic brake booster. Pirtek did this for £60. We replaced the old power steering reservoir which had too many ports with a Noble M12 reservoir which is the same as a BMW, Landrover, ford etc.......

We removed the ABS module (although you can keep this) and fitted a brake bias valve.

Fitted a 'rigid' vacuum pipe with a one-way valve to the inlet manifold.

We made brake pipes from the master cylinder down to both front callipers. A pipe from the master to the proportioning valve then a pipe from there to the t-piece just in front of the rear diff.

You could probably get away with bending the existing pipes to fit but it will not look great and there is a chance the pipes will crack on these old cars.

Think that was it!

[steverrquattro]

Do you have a picture of before and after?

[jsws3]

Excellent mate another mod to add to my list .

[jsws3]

Do you have a picture of before and after?

Is yours not done on the swb ?

[steverrquattro]

Is yours not done on the swb ?

It is and quite a neat job too, but using type 85 parts. A tip on the hydraulic pipe is to use the existing one and just get it shortened.

[DamoM]

Do you have a picture of before and after?

Not great pics I'm afraid but all I have:

Old setup with brake bomb etc. Abs had already been deleted.


New set up

[adam g]

I see that neither of you moved the master cylinder to the opposite side of the car, (removing the blanking plate) only curious as I had heard this was of benefit too through reduction in distance/losses between peddle and MC. However, if the improvements are as substantial as you say with out doing this then why make the job more difficult.

[DamoM]

I see that neither of you moved the master cylinder to the opposite side of the car, (removing the blanking plate) only curious as I had heard this was of benefit too through reduction in distance/losses between peddle and MC. However, if the improvements are as substantial as you say with out doing this then why make the job more difficult.

Yeah I had always assumed that this was the main culprit of the vagueness in the pedal feel but the braking feels as responsive in this as any other car I've driven so I see no reason to change it. For me though there were also issues of room and heat as this side has a big turbo sat on it and hot downpipe. All the space on these I5s is on the inlet side! There was especially loads of room after we were able to remove the bomb and the valve that it screwed into!