ATRATB039 02/01/1991 A/T - G4A-EL/4EAT Low Pump Pressure

Referencing the parts I show here:
https://www.feoa.net/modules.php?name=Fo ... ic&t=61316



This is a very easy fix to do. First thing you do is remove two splash shields to reveal your transmission oil pump. It's the rusty thing in the middle of the picture below:




You are trying to remove the bolt circled in red below. As you can see, you can not use a ratchet on this. A 21MM open ended wrench or crows feet would be my first two choices. Since I didn't have either one of those, I used an adjustable wrench. It would probably been easier to remove the wheel, but I did not do this because I already had the car jacked up.




Once you have removed the bolt, it should look like this:



Very little fluid will come out when you remove the "valve" and spring, maybe a tablespoon. But you will still want a pan there:




Here is a side by side comparison of the "valve" with the new one on the right. Note that the end with the hole in it goes into the pump first with the hole on the upper side (like shown).




This is a side by side comparicon of the springs, with the new spring on the right:




This is a very easy fix to make and I do recommend it. For comparison purposes, it is much easier than an engine oil change!

Also note that there is more than one manufacturer for this fix kit, so your might look dirrerent. The one shown above is Transgo F4A-valve.

In case it's not already obvious, this is a fix for an automatic transmission whereby it slips on startup after sitting for a while. Essentially the new valve and spring boosts low rpm transmission oil pump pressure. That and there is no new gasket provided, it appears to just use a metal ring around the bolt, which I just reused.

I installed one of these yesterday. Got my son's '93 LX Wagon back on the road. Easy to install, if the old valve plunger falls out and you don't know how it was oriented, the cross-drilled holes are at the top.

Please watch the dates on these posts and try to not bump old threads.

Trouble with getting the valve out

I read this post about this valve repair and thought that I would try this fix. It sounded just like the fix the car needed.

I got the plug out and spring out without any trouble, however, the valve is stuck up inside and I can not get it out on top of that the fluid that came out while I was trying to get the valve out amounted to about a pint, so now the car doesn't move at all. I'm guessing that the only reason that it was eventually shifting is that the fluid below the valve was allowing it to shift once it was warmed up, but now since there is no fluid below the valve the car won't shift into gear at all. The valve seems to be stuck up in there pretty good. The thing is nice and shinny up in there. I'm not sure why it's stuck, but it's sure not coming out right now and the car isn't moving anywhere right now either.

Does anyone have a trick to get that valve out?

I had a stuck one like this.
I heated the tip of an old screwdriver and bent it into an 'L' shape. I then hooked it into the ledge at the bottom hole in the stuck piston and used a pair of pliers slid down the screwdriver shaft to pull the piston out slidehammer style.
I found that the piston in my tranny was stuck in its bore by a small steel shaving. The tranny shifted perfectly after installation of the new piston and spring. Good luck with yours!!

I forgot to mention that you should make sure that nothing remains in the pump bore that might stick the new piston and that the new piston moves freely in the bore without hanging up. I flushed the bore on mine using diesel starting fluid ( my favorite spray solvent), but spray brake cleaner or similar would be fine.
If you find that the bore is nicked or scored so much that the new piston sticks, a makeshift hone can be made by cutting a slot in the end of a pencil or other small wooden dowel and putting a piece of suitable grit wet+dry sandpaper thru the slot and honing the bore lightly. Besure to flush the grit out again after honing.

At this point the car is not shifting at all. We pushed it up higher into the driveway and a bit off to the side. The weird thing is that the transmission fluid dip stick is showing that it is full.

I had tried to make a pick from a heavy duty coat hanger wire with the pick end turned down and being pretty short so it would not bend easily. We put a bit of downward force on it but stopped before we thought we would break something.

I was looking at the posted photos of the F4A-Valve and originally thought that the holes in the side of the valve toward top of the valve were just flow holes for fluid but then thought in the back of my mind that there could be some sort of pin or needle valve that was locking it in up on the top and because I wasn't sure I stopped before I broke something off from pulling down on the valve.

How hard can I torque on that valve ? Can it be pushed up and then down or would pushing it up just cause more of an issue ? Is it already at the top of its cylinder ? It's pretty far up there. Can the transmission fluid pump be unbolted from the side without having to remove the whole transmission ?

I'll give your suggestions a try in the meantime.

By the way, Thank You whoever thought to post those perfect sequential pictures. They were a fantastic help. Thank you again for your ingenuity.

And thank you to all of you who so promptly posted your thoughts to help me out. I really appreciate all of your assistance and input. Thank you all once again. javascript:emoticon('')

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If your piston is truly stuck as mine was, a coathanger wire ain't gonna git it done. Something truly heavy and strong is required, like the screwdriver/tool that I described in an earlier post. With this tool, you can exert strong pressure by pulling down on the screwdriver handle and additionally you can add impact/inertia to your effort by sliding a weight down the screwdriver shaft into the screwdriver handle. I used a pair of slipjoint pliers as my slidehammer, but a heavy socket might be even better.
There is nothing to be broken by using strong downward force to break this stuck piston free. The only part that you are acting on is the piston itself and you are changing it out with the new/improved one anyway. Keep trying!!
It is not necessary to dismantle anything further to remove this piston.

Since you may have trouble finding this part:


http://www.transmissionpartsusa.com/F4A ... 033933.htm

GOOD stuff thanks for posting it up didnt know the trans needed addressing.

I have a 91 ford escort 1.9 with auto trans and my piston is stuck up in there also .. If its stuck then wouldn't that cause it to shift weird ?

Yes, for proper operation, the piston must be freed.

Thanks for the response, Guess tomorrow I will try a little harder and get that sucker loose. It's an old car and not so pretty anymore ha ha but dang the motor just purrs like a kitten hate to give up on it. Will post tomorrow on my outcome .....

Took an act of congress but finally got it to pop out lol ...... Couldn't see why it was sticking cause of if being to dark outside just need to get a new one and see what happens......

the kits still avaible?