MK3 / MK4 brake system interchangeable?

[axxez]

Hi there!
I am having problems with my breaksystem, in particular the master break cylinder and the break booster, so I want to renew them. Problem is, that the booster is not available anymore (cylinder is thouh), only very few used ones in bad condition. My Transit is 1990 and there are parts available for a 1991 Transit which might be interchangeable.

Original parts for the 1990:

Cylinder:
https://www.motomobil.com/products/haup ... 61510440-7

Booster:
https://www.motomobil.com/products/brem ... 510540-1-h


Parts for the 1991:

Cylinder:
https://www.motomobil.com/products/haup ... 67546920-1

Booster:
https://www.motomobil.com/products/brem ... 546950-1-h

[axxez]

So the idea is to either fit the 1990 cylinder, which would fit the pipes and the reservoir to a 1991 booster. Or fit a 1991 cylinder and booster to the rest.


Questions:

1.
The 1990's cylinder has a 40,7mm connection to the booster. What is the sice of the 1991's cylinder connection?

2.
The 3 break-lines differ in screw-size, which should be ok by using an adapter. But which line fits where? Is the funcionality the same between the two cylinders?

3.
Does the fluid reservoir fit?

[Ralph.9]

I have new brake booster's?

[axxez]

The 86VB2A159AA? Where did you get this from? A source would be very appreciated, I didn't find anything on the web..

[axxez]

The Mk4 is 92VB2A159AA

[axxez]

News: I just talked to the guys at Motomobil and let them measure the booster. Seems that the important parts fit, which means diameter of the center hole that connects to the cylinder (40,7mm) plus the distance between the screws (70mm center to center).
--> I will give it a try and keep you informed if it works.

[Chug]

I've fitted mk5 m/c to mk4 so the servo booster should fit too, but not sure.

[axxez]

Update: The master cylinder fits the booster. Might do the repair by tomorrow, so lets see how everything else fits.

[Ralph.9]

The 86VB2A159AA? Where did you get this from? A source would be very appreciated, I didn't find anything on the web..

I have a few new ones in stock.

[axxez]

Too late But thanks anyway, I started a thread on a german forum, so if anyone is interested they will be linked here.