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Having owned my '84 Euro S twin-dizzy 16v auto 928 for 2 years now, today I replaced both flexible vacuum hoses for the auto transmission, and can't believe how smoothly these cars can shift.
Mine was always a little abrupt and clunky and just thought it was the way they were, but after noticing it was a little worse recently, I did a little research and decided to check the flexible vacuum lines that connect the hard lines together and to the trans itself.
Well, the front one cracked in half when I touched it and the rear one slid off the port with hardly any force applied.
I was able to replace both just by jacking up one side of the car using a lift at and a jack-rod.onnmy jack. I achieved enough access just by removing the heat shields and the cross bracws that they attach to and using a long 90 degeee needle nose pliers to work the silicone vacuum hoses onto the metal hose ends.
The shifts were.most abrupt at light throttle and slow speed so I drove it around the neighborhood and couldn't believe the difference. I'll do a more extensive test drive on the open road soon, but expect it will be great.
Front one shown in 2 pieces & rear one is the long one that goes up over the transmission.
I've replaced that on my 89 after I had every failure for that modulator.
Nylon line near the engine melted shut, both of the braided vacuum lines were cracking and failing, modulator diaphragm failed, and the piston it actuates broke.
Saying that replacing and fixing all of that with fresh parts was fantastic is putting it lightly. Really made driving at low speeds so much nicer.
I highly recommend that anyone who hasn't already should replace those vacuum lines. You will have to "hug" the transmission to do that one though...
I've replaced that on my 89 after I had every failure for that modulator.
Nylon line near the engine melted shut, both of the braided vacuum lines were cracking and failing, modulator diaphragm failed, and the piston it actuates broke.
Saying that replacing and fixing all of that with fresh parts was fantastic is putting it lightly. Really made driving at low speeds so much nicer.
I highly recommend that anyone who hasn't already should replace those vacuum lines. You will have to "hug" the transmission to do that one though...
Yep, it's tight up there if you don't remove the exhaust and only move the heat shields like I did.
Drove it last 2 days though and it's fantastic - what a difference.
This fall I replaced the A/T vacuum line by running brake line cunifer down parallel to the rear brake line (there was a vacant channel in the guides). I read this tip somewhere here on Rennlist. Agreed the shifting difference was profound.
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PSA - Replace your A/T vacuum hoses!
