700R4 Issues

[CamaroAdam73]

So this has been an on going battle since the day i bought this transmission.

It's a 700R4 post-84 30 spline count transmission, I've replaced and re-ran the transmission lines 3 times, and one still leaks.

It leaks from the Fitting on the side of the transmission, where the line feeds in.

On all three occasions of changing the lines i bent first, then threaded into the transmission FIRST, then the radiator, the lower line still leaks, very very very VERY slightly though, and it only happens when the car has been sitting, not running for awhile? and the amount it leaks is not that noticeable, but it's a transmission leak non the less and i'd feel allot better just taking care of this once and for all.

 

[Blake442]

Are you bending and flaring the lines yourself?

In my experience with making new lines, they often leak when first installed. I usually end up having to loosen and re-tighten them a few times before they decide they want to seal properly... Might be worth a shot.

 

[robwkamm]

few common issues that cause this. 1. fittings that go into trans case are pipe thread. use tape on those. not the flare part.2. the trans dip stick tube leaks look the same as a hose leak. make sure thats not leaking. it sounds like it to me because it only leaks when your sitting off.. 3. make sure the detent cable is not leaking. were it goes into the case. can look like the hose. my money is on the dip stick tube. lokar makes a sweet flex dip stick set up .just a few thoughts. hope it helps

 

[dunc6666]

Just went through the same problem on our rebuild. Re-used old transmission lines and they leaked at the flare fittings on the 700R4 after start-up. b*tch of a spot to get a wrench on and couldn't tighten enough to stop leak. Replaced the old solid steel lines with flexible stainless braided with swivel fittings and was able to tighten up really well and no leaks so far. More $$ but saved my knuckles!

 

[CamaroAdam73]

Dunc6666 Could you please send me a link to the website that you bought those lines from? i've been searching for flex-trans lines for awhile now, I re-tightned down the transmission line that was leaking and the problem is solved. But either way i want to get rid of the solid lines anyways.

Also, there is STILL a very very VERY small leak, the damn dipstick housing, i've been fighting this since day 1 with this car.

I bought a flex-fit transmission dipstick, but it won't seat it all the way! It goes in a good 1 1/2 - 2 inchs but doesnt clear past the two O-rings built into the stem of the dipstick housing, i can't get it in any further and this is really aggrivating. Any advice?


Oh and just a tip, i've done the lines on this 700R4 about 10 times now, the easiest way to do them, is to dis-connect them from the Radiator first, it makes it allot easier to get them to seat in on the transmission end, re-connecting them to the radiator is a walk in the park.

 

[dunc6666]

I bought the lines through McMaster-Carr. I will forward the part number when I return to work next week. Can't help you with the dipstick leak. I guess we lucked out. Had to use a different dipstick from another vehicle, changed o-rings and everything seems good so far. Not too many miles yet, solving other issues.