78 euro parts on 81 us?

[78porsche928]

hey guys, so i have a 78 euro project and a 81 us project, i finally got the the chance to clean the fuel tank and lines on my 81, and then took the car to the Autobahn, Stamford, Ct, and had them work on the wiring, electrical system. I finally got the car runing yesterday, but then discovered that my brake booster was seized (and the brake pedal does not pivot, its froze as well) and some of the wires going to the instrument cluster get hot when connected. before i take the other car apart, do you guys know if the brake booster, brake pedal and instrument cluster will work on my 81 u.s from a 78 euro? i will also put up pictures when i get home to show you guys where i am with my project.

[MPDano]

I would say it probably would work. Both have normal early brakes. Once you get into "S" territory, the Calipers, Master Cylinder changes on the later S. Probably the Booster too, but not sure.

[78porsche928]

Originally Posted by MPDano

I would say it probably would work. Both have normal early brakes. Once you get into "S" territory, the Calipers, Master Cylinder changes on the later S. Probably the Booster too, but not sure.

thanks, what about the instrument cluster? i noticed the gauges are not the same, would the wiring be different as well?

[MPDano]

I would be hesitant to put a different year or even different type (US/Euro), especially since it's electrical. The connectors might fit but smelling burning wires is never good. Stay with like year and types for Clusters.

[Danglerb]

Quick idea is to look up the parts and see if the numbers change, but I suspect lots of small differences from a 78 cis car to a 81 Ljet. Lots of things changed between 79 and 80 too, so in general I would start with the premise it won't work until proven otherwise.

Hot wires mean an overloaded circuit, NOTHING in the pod uses much power, so we are likely talking a short someplace. (except for the ignition key in some cases).

[78porsche928]

Hey guys so I found and ordered a good instrument cluster for a good price on ebay, I am currently in the process of removing the brake booster, I unbolted everything and moved things out of the way but it just won't come out, is there a trick to doing this?

[DPW928]

The 78 model year used two different boosters and master cylinders. If the booster is the same diameter on the 81 and 78, they should interchange. If different diameters, the interchange will require modifications and may not provide satsfactory braking.

[78porsche928]

Originally Posted by DPW928

The 78 model year used two different boosters and master cylinders. If the booster is the same diameter on the 81 and 78, they should interchange. If different diameters, the interchange will require modifications and may not provide satsfactory braking.

I called porsche and they told me they have the same part number, 81 and 78, I might have to buy a new one though, I think I destroyed it when taking it out of the car. Is there a trick on removing the or installing the booster without braking it? My neighbor told me that I have to lift the engine up and move it to the left a little bit, but I am hoping that's not the only option I have.

[DPW928]

The early (smaller diameter) is NLA, which may explain why the dealer is saying they are the same.

The booster can be removed without removing the engine but it requires small hand, a lot of dexterity, and a large vocabulary of cuss words.