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Discussion Starter #1
Guys, with The C4 + converter removed can the front pump seal be replaced without yanking the pan, pulling the valve body etc?

I’m going to pull the tranny (4th time). It’s been stable driving very well...all other leaks nonexistent except inside the bell. Have a trans shop that will do it brought to them off the car for 150$. But wondering if I can pull it and reseal myself without disassembly. C4 was given to me rebuilt with purchase of the car. It’s got a new stock style torque converter. It’s all been run about 1,000 miles since last spring with a stock-ish 302.

Just as reference these were the photos of one of the times it went in and out back in April.
 

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Yes, it's pretty easy to do. I have the Mac Tools version of this puller, but the concept is the same. Stick the small hook into the seal, turn a bit and whack the "L" with a hammer.

 
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Discussion Starter #3
Yes, it's pretty easy to do. I have the Mac Tools version of this puller, but the concept is the same. Stick the small hook into the seal, turn a bit and whack the "L" with a hammer.

Very cool! I'll get this if I decide to do it myself. Do you do that while the shaft is on or take it out first?

But, the big butt....is that I'm starting to realize reading all these threads is that the bushing should be replaced with the seal. No idea of the rebuilder replaced that or not. You'd think anyone doing a proper tranny overhaul would. But this new seal started leaking after it had a bad torque converter that was shaking on it from the get go. New converter fixed everything but then this pesky leak appeared shortly after. Perhaps the bad conv tore at the seal. Uggh if there's one thing I hate it's repeatedly pulling the tranny to see what works next!
 

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If the new converter is snug in the bushing, you probably don't need to replace it. You won't need to remove the center shaft to pull the seal. You can even drill a 1/8 hole in the edge of the seal and use a slide hammer.
 

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Discussion Starter #5 (Edited)
If the new converter is snug in the bushing, you probably don't need to replace it. You won't need to remove the center shaft to pull the seal. You can even drill a 1/8 hole in the edge of the seal and use a slide hammer.
Good to know! I've ordered a National 3404 Seal from two suppliers in case one is wrong or messed up. Going to drop tranny swap seal. Lube the hell of that thing with vasoline, reinstall and fill on the Army lift this weekend. Hope like hell this doesn't turn into another transmission nightmare. If it's still leaking inside the bell I'll just give up and take it to a dang shop!

Hope like heck the 3404 is the right seal. Seems to be what all the parts vendors are selling.
 

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+1 Replacing the busing when it is not necessary leads to the possibility of incorrect installation and failure. In this case if it ain't broke , don't fix it. You can also "carefully" remove the bellhousing ( and replace the bolts to hold the pump in place) to make seal removal/ installation easier. CARE must be taken to not dislodge the pump.
 

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Discussion Starter #7
+1 Replacing the busing when it is not necessary leads to the possibility of incorrect installation and failure. In this case if it ain't broke , don't fix it. You can also "carefully" remove the bellhousing ( and replace the bolts to hold the pump in place) to make seal removal/ installation easier. CARE must be taken to not dislodge the pump.
That’s good to know as well. But since I’m not leaking externally between the bell and pan I’m going to try to leave that seal alone. I’ll take a leap of faith that the rebuilder replaced the bushing and that my early installation technique attempts (plus the old dud of a converter) shocked the current seal. If this new reseal doesn’t fix it I’ll probably just get a shop to do a pump and bushing replacement. I’m tired of leaks and pulling this thing.

I’m going to need to lube that seal when I do the ‘3 step click’ installing the converter. So I guess Vasoline or silicone “sil-glide” gel for brake parts is best?
 

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Vaseline. Also pack the backside of the seal. Fill the opening up. Sometimes when knocking in a seal you can jar loose the "garter spring" on the backside. The grease will help prevent that. The actual seal surface just needs a small swipe. Also a light coat on the converter neck. Vaseline dissolves into ATF, save the SilGlide for other stuff. Professional transmission assembly lube is essentially just colored vaseline.
 

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+1 EXCELLENT advice. That garter spring has become dislodged more than one on me. To the point where I made special tools to reinstall it. Now I just use Vaseline like GypsyR stated.
 

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Forget the national seal Go to your local Ford dealer and order part #F2VY-7A248-A. This is a double lip seal with a more robust design than the National seal. When you get it you will see the difference. You can see the bushing with the seal removed if its not scored its probably OK. Use vaseline as Gypsy advised
 

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Discussion Starter #11 (Edited)
Forget the national seal Go to your local Ford dealer and order part #F2VY-7A248-A. This is a double lip seal with a more robust design than the National seal. When you get it you will see the difference. You can see the bushing with the seal removed if its not scored its probably OK. Use vaseline as Gypsy advised
Gahhhh! Now you tell me after I double ordered 40$ of parts o_O I will check with the local Ford dealers, thank you!

Edit: It's on order I'll get it tomorrow afternoon! Great tip.
 

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Discussion Starter #12
Vaseline. Also pack the backside of the seal. Fill the opening up. Sometimes when knocking in a seal you can jar loose the "garter spring" on the backside. The grease will help prevent that. The actual seal surface just needs a small swipe. Also a light coat on the converter neck. Vaseline dissolves into ATF, save the SilGlide for other stuff. Professional transmission assembly lube is essentially just colored vaseline.
Will do!
 

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Discussion Starter #13 (Edited)
So I got that Ford seal, that puller (worked great!) and a tub of vasoline! C4 came out today at the shop and after dutifully draining the converter could clearly see it was leaking a slow steady out the bottom of that seal.

now comparing the Ford seal (which is going to be the one going in of course) it’s pretty close to the National seal. But this seal I pulled out is markedly divergent from the other two. One guy passing by said it looks just like the one on a 4R70W.

The inner bushing race looks good while the outer one in the pump groove has a rough spot where the leak was. Shop foreman said to clean and polish it with emory cloth.

Black seal is the Ford seal
 

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Discussion Starter #14
We also noticed that the national and Ford seal had a much tighter fit over the converter snout than this orange seal I hooked out of there. That thing completely lacks the extra outer rubber flange which will sit right where the previous one had a metal ring only against the pumps housing. It was leaking from that metal ring too.

Will find out tomorrow if this fixes it after reassembly! ???
 

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Discussion Starter #15
I’ve buttoned her up. Idled for about 1/2 hour to get fluid hot level it right & drove in a mile left it at work. No leaks so far! First time I’ve peaked under and seen no red since the initial build up last year ?

Ford seal went right in by hand with the Vasoline just required a light tap all around with the back side of a drift and mallet to fully seat. Pretty sure that old seal was either wrong or a very cheap one. It has no rubber outer race lip like the Ford or National seals do.

Thanks for all the advice! From the tool, to the part # to the Vasoline trick this turned out to be a killer helpful thread. Hope others will benefit from it too.
 

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Glad you got it sorted, had my trials with automatics over the years as well. I had a C-4 that would religiously blow out about a half quart in the exact same place on the highway every time I drove home from college.
 

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Discussion Starter #17 (Edited)
Glad you got it sorted, had my trials with automatics over the years as well. I had a C-4 that would religiously blow out about a half quart in the exact same place on the highway every time I drove home from college.
Wow, sounds like it was either posessed or had a load bearing issue highlighted by the same spot each time. As much in & out as i've done with this C4 it is original came rebuilt and runs great + I've winnowed down all the leaks (new straighter pan + RTV), then the kick down linkage (new outer o-ring; actually it was missing ha! Unsure if that was my brain fart or the rebuilder) and now the front seal. That front seal was definitely just an incorrect or cheap part. Hopefully the internals aren't like that. If I only get 4-5 years out of this c4 it was worth the trouble.

But if I ever have to go through a whole rebuild with this car again I'd probably go for a later well built C4 with the reinforcements or a good AOD swap. Wouldn't do manual on this kind of coupe. If I ever get a Fastback or GT car (I need to play lotto more often) It would definitely be a 4 speed toploader!!
 

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Discussion Starter #18
Guys, after 2 weeks and about 200 miles of driving I have to say this was a total success. I'm still getting tickled when I look under and see a completely dry tranny with no red :) Thanks for all your advice and solutions.

The only scary part was all that Vaseline that got hot ran out and then solidified back on the ground :p But that was the key trick here as was having the right seal. So a big thank-you! to all especially to GypsyR and Ford Tech!
 

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jsbenami, thanks for this thread. I just rebuilt my C4 and after re-install and test driving, it's leaking from the pump seal.. uggh! I'm going to put in the Ford seal when I pull it again in a week or two. I also appreciate the link to the seal puller tool.
 

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One other "tip". I always use a NON flanged seal on the pump and make sure it has the orange silicone rubber for the seal material.
Randy
 
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