85 Chevy anyone?

does anyone have an 85 chevy that can tell me where the vaccum line goes when it leaves the manifold to go to the vaccum modulator for the trans? I cant find it anywhere and i need to check it for a leak. also where is the modulator on this car..(not sure which trans it is.. so if you can give me a hint so i can look, ill tell you which trans i have.

Also, why are there hoses running from my steering box, to the master cylinder?

 

What engine & trans is in that car???

 

its a chevy 305 and not sure which transmission, we had a huge discussion on here one time, but we never decided which trans it has.


the problem is it shifts in and out of OD when it wants, usually when pulling a hill, and shifts into 2nd too early. There is a vaccum leak causing the dampers to do their own thing in the dash, while pulling hills, so im hoping its a vaccum leak causing the modulator to do things on its own also.

i want to replace all the rubber vaccum lines under the hood, but havent had a chance yet.

 

Well....unless it has been changed it likely has a 200 4R. Doesn't matter...it could have a 700R4, too, I suppose, but, you said it has OD so either way ...it doesn't have a vacuum modulator. It uses a TV cable.

 

no damn wonder i couldnt find a vaccum line.. hahaha

well crap. wonder why its acting nutty?

The story is i had a check engine light, due to the electronic something in the carb. The control for that had blown a fuse, so i was running in limp.

Once the carb guy fixed that, the trans started shifting funny, and by funny, i mean by 10 mph im in 2nd gear and lugging. the rest of the gears shift where they are supposed to. then when im in OD and start up a hill, it jumps in and out of OD till the hill is topped.

i pulled the tv cable and put the tiniest zip tie i could find around it which was about an 8th of an inch, and that made 1st hold way too long, then pop into 2nd, so on the side of the road in front of the house i cut the zip off and came back home. that was bakc in the spring and i havent fooled with it since.

 

Those adjustments are touchy and any adjustment that is way off can cause damage. I am having an old timer's moment here but should come up with what that problem is....maybe. I think Joe Padavano would know....may want to PM him. I had similar problems but, for the life of me, I can't remember what the solution was. It sounds like the converter is kicking in and out..... something about that switch on the tranny comes to mind too??? I will say that it is probably best to not mess with it until you find someone that KNOWS these trannies and carb systems. My wagon was an 88 and could be different but I don't think so. Although, I had the Olds 307 engine which I am ASSUMING you have.
I will try to remember, Jase....meantime....try to PM Joe. Pretty sure he would know.
Sorry I couldn't be of more immediate help.

 

The converter lockup function in the ECU uses the Throttle Position Sensor in the carb in addition to most of the other sensors on the engine. If you are getting codes related to the TPS or other fuel system sensors, the lockup function won't work correctly. Fix the primary problem first, then see if there is a real problem with the trans. As noted, the Throttle Valve cable on the trans must also be adjusted properly. If not, the trans will not shift correctly and may be damaged over time.

 

im no longer getting codes, i was getting a check engine light due to the electronic fuel control, or choke, or something. So once that was corrected, is when the funny shift started. As long as it was in limp mode it shifted almost normal.

is the chevy cable set the same way as the ford? pop the clip, push the pedal to the floor and lock the clip back?


That would help the 1-2 shift, but wouldnt explain why shes in and out of OD when pulling a hill, or maybe it would, dont know thats why im here hahahah

its an H engine code which is the chevy 305, not the olds 307

 

to joe,

Is it hard to replace the lockup converter in the 700r4? I remember years back, my Riviera wouldnt stay in lock up, and thats what the wagon is doing now.


To update The only vaccum leak i can find is in the dash for the heat/AC control and ill get around to fixing that. The check engine light was a speed sensor fault, that must have been a loose connection, with driving the car, that has gone away and the trans is shifting nicely.

nicely enough for me to run into the back of a man today going thru an intersection. he was a smartass and slammed on brakes because i was too close.. so now, im looking for an 85 caprice grill...... Anyway, as of tonite, the only problem is it doesnt want to stay in lock up

 

The more likely problem is a bad lockup solenoid valve in the trans. The solenoid should be very easy to replace once the trans pan is off.

 

maybe thats what he replaced and not the lock up converter. it resembled the cigarette lighter whatever he replaced in my riviera.

 

Something like this?

 

didnt look like that as i remember, it looked more like a cylindrical cartridge of some sort. i know he had to drop the pan to change it.


Is it possible, for the transmission to try and stay in lock up in all gears? thats what it acts like its doing, whether its possible or not.

 

ok, been driving this car all week, and its staying in lockup in all but 1st gear. when i shift into 2nd its already in lock up which is lugging the engine. i can tap the brake pedal to bring it out of lockup, but as soon as i release the pedal, back into lockup she goes in any gear.

is this a sign of a bad tcc solenoid, or is there something somewhere else awry telling the solenoid it should be in lock up?

 

finally talked to a transmission guy who says it sounds to him like the pressure switch that operates the tcc solenoid is the culprit. im driving the mercury for now, so ill get around to the chevy sometime .