My C4 losing tranny fluid at the rate of at least 1 quart per week. There is never any drops on the driveway or garage floor ... guess it only comes out when driving ... Any idea where it could be coming out that fast? I am swapping the engine over Thanksgiving Holidays and gonna try to get somebody to rebuild it quick while I got the engine out but figure I could conserve a couple gallons of Type F prior to that ... Dan
could be the mod valve and the engine is burning it ?? check the vac hose see if it looks wet ...but if it only does it when it moves after the shift....then it might suck the line clean ....but you should see a little....or could be coming out the vent on top ...by the time you get slowed down it blows off look under the car around the floor pans and trans
worse case tranny fluid leaking into the radiator tank? but then again if it was a 1/4 a week the radiator would be overflowed
Earl told me to check the mod valve also .. his car had disappearing fluid as well and the engine was burning it .. Car has a new radiator so it isn't that ... I do think I saw fluid in the vacuum line when I had it off a few weeks back ....
Just pulled the vacuum lines and lots of fluid ran out. Gonna go down to the parts hose and get a new one ...
Great info learned here. I'd never even heard of the symptons and surely wouldn't know to look at the modulator. I love this board, maaaaann.
Picked up the new modulator tonight ... didn't have time to install so it will have to wait until tomorrow. Interestingly the box the new one came it says to replace ever 10,000 miles ...
well, the diaphragm can get wore out, but after 10k miles? Myself, I prefer the adjustable modulator valves, but ATM my C4 has the 'non-adjustable' modulator in it... once that sucker craps out, tho....
My original is the double diaphram ... double vacuum line version of the modulator. I am replacing it with the same since the vacuum lines are just the right length and in just the right position to attach correctly. I would have to run a new line or extend the current one to get it connected to the single vacuum version which has the port on the back instead of two on the top. The one I just bought at Autozone is adjustable ... the one I pulled out is not ... Hopefully it is adjusted properly so I don't have to monkey with it in the car ... the tranny mount makes it tough to get to and I don't want to bother unbolting it ...
It's in ... thanks guys. Not only does it shift smoother but it seems the engine is running better also ... I guess it helps to run on 100% gasoline and not a gasoline/tranny fluid mix ...
Dan; it does give the engine a vacuum leak. That is probably why it ran a bit rough. Glad you got it fixed.
