CD4E air check

Joined
Aug 30, 2015
Messages
11
Likes
0
Points
1
Age
49
#1
Make
Ford
Model
Escape
Year
2008
Miles
150000
Engine
2.3L
Rebuilding a CD4E from an ‘08 Escape. Someone didn’t pay attention to line up oil holes at the direct drum bushing with the reverse clutch hub, and ruined the bushing. Also a weld broke on the direct shell, may due to high line pressure? Anyway I completely rebuilt and added valve body improvements, updated direct drum, etc. the drum I bought was a reman, rewelded where it sometimes cracks

I’m not happy with the air check I am doing. Set assembled drum/clutches/etc on pump (yes all sealing rings and new pistons and bearings and such). Lubed up good with STP. 40 psi air shows all clutches to apply, but some cross leak on all circuits. Also pretty good leak when I test converter/cooler circuit with thumb over pump support snout. So I remove drum and just check pump itself for cross leak by plugging holes in pump support/stator. Way less leakage then, but still a little on all circuits.

Obvious to me there are pump cross leaks and sealing ring cross leaks both. I disassembled pump and flat sanded body and support carefully with 220/300 sandpaper on a flat 3/8” tempered glass surface. Eventually got a nice smooth even sanding pattern all over after lots of work. Reassembled with gasket and plate (yes I have correct gasket). Not a significant improvement but maybe slightly better.

To address sealing ring cross leaks I reinstalled the old direct drum as it only had slight scoring on the outer wall and snap ring groove was intact and no cracks. Seems to have less for cross leaks but still not impressive.

Maybe I’m expecting too much from air tests. I’m used to a 4L60e being very leak free on air tests. Maybe these CD4Es just act different. Any opinions?
 
Joined
Nov 14, 2006
Messages
1,594
Likes
18
Points
38
Location
Nothern California
#2
Hang in there. We only have a couple really good trans guys here. They are busy and sometimes it takes a few days for them to read a post.
 

grcauto

Hero Member
Joined
May 29, 2014
Messages
517
Likes
32
Points
28
#4
I'm retired now and relying on my memory, which is not a good thing, but it seems some leak during air tests was normal with those but not to much. It shouldn't be excessive.
This guy is a very good tranny man and you can ask him about this in the comments of the video. He is very helpful and will answer your questions.
 
Joined
Aug 30, 2015
Messages
11
Likes
0
Points
1
Age
49
#5
...it seems some leak during air tests was normal with those but not to much. It shouldn't be excessive.
This guy is a very good tranny man and you can ask him about this in the comments of the video...
Thanks. I have watched his videos many times and he is a big help. I have tried to listen to his air test vid but the audio during his test is just not helpful. I will message him and see what he says and share here.

Also I do expect less than perfect seal in air tests. As a novice I just don’t know what is excessive. Hard to quantify but some cross leaks with drum installed sound/feel like as much as blowing hard through a soda straw. Some circuits are slightly less than that. And pump-only cross leaks are a lot less than that, possibly like blowing through a tiny coffee stirrer/straw whatchamacallit. I know it’s designed to work with fluid and not air, so I don’t expect perfection. But it seems pretty leaky to me - enough so that some adjacent clutches apply if I plug the other circuits. Spinning drum and adding more STP to seals and such does not seem to help.

I have inspected the drum inner bore and reverse drum and the surfaces that sealing rings contact look perfectly smooth with no grooves. Pump support shaft inspected and measured and I just don’t see any smoking gun there. Perhaps the way Ford builds these they just don’t seal well without ATF and pressure.

Attached are some photos. Not really relevant to my cross leak problem but may help others in future. First photo shows old drum (left) and reman drum (right). Note welds on reman drum snap ring area (near bench surface in photo) and weld on inner hub (second photo). The inner hub tends to crack and the snap ring blows off. This eBay seller sells these welded units to address those issues, though the valve body might be the real cause of this. Third photo shows hub broken off direct shell that ultimately caused loss of gears 3 and 4 (I did not know the hub and shell were supposed to be on piece until I received the new shell).

F7A3FBC0-525F-416E-9FE2-1929D88683AA.jpeg 195AAC1A-9E0A-4C11-ABD6-2A40209A47CA.jpeg 3CDFAEAA-8217-41C0-B5F0-100D0657F09E.jpeg
 
Last edited:
Joined
Aug 30, 2015
Messages
11
Likes
0
Points
1
Age
49
#7
The ATSG manual says “do not apply air pressure” for the converter clutch bypass circuit (that exits out the end hole of the pump support shaft). So perhaps I need to ignore the fact that air escapes from this circuit out the pump gear ports. See attached photo. Even if that’s the case, still wondering about the other cross leaks in support shaft and clutch circuits.

8B6D17BD-5060-4F01-B239-757611C55BC0.jpeg
 

bp042665

hunting nut
Joined
Nov 26, 2012
Messages
623
Likes
12
Points
18
Location
Iva South Carolina
#8
the drum you got could have to much clearance I always buy a new 1 from ford have seen this before also check the hub shaft clearance
 
Joined
Aug 30, 2015
Messages
11
Likes
0
Points
1
Age
49
#9
Thanks for input. I’m inclined to doubt it’s a drum problem since both drums leak about the same, but then again neither are new, so who knows. I did not have a way to measure ID of drum hub but both look smooth and good. Ford dealer wants $440 for new OEM drum so I’m not intending to go that route. Would consider new aftermarket maybe. After I get back from vacation next week I plan to try to get some perfectly sized o-rings to temporarily replace the support shaft sealing rings and see if I can eliminate the sealing rings from equation to ensure pistons are sealing well. I could just slap everything together and cross my fingers but I want to get it right the first time and make sure I share this info for others benefit.

Stand by for more.
 
Joined
Aug 30, 2015
Messages
11
Likes
0
Points
1
Age
49
#10
Thought I should update this thread with my results. I couldn’t find o-rings to try temporarily so I improvised and put some aluminum foil under the support shaft sealing rings to force the sealing rings to make tighter contact with the drum hub. This seemed to improve things but of course was not a real solution. I also sanded the pump plate as it was warped, but it did not improve the pump cross leaks much. I finally watched some YouTube vids of folks air testing other models of transmissions and they seemed to have similar air leaks and were not concerned about them So I threw my hands up and decided to just install the transmission.

I am happy to report that the transmission appears to be operating fine. Shifts through all gears at the appropriate speeds and all is good. I suspect the sealing rings just need atf and conditions that exist when operating to seal well. Not sure about the pump cross leaks but it works so I’m going to stop spending effort worrying about it. Thanks for the replies.

Hope this helps someone else and doesn’t steer them wrong.
 

grcauto

Hero Member
Joined
May 29, 2014
Messages
517
Likes
32
Points
28
#11
Thought I should update this thread with my results. I couldn’t find o-rings to try temporarily so I improvised and put some aluminum foil under the support shaft sealing rings to force the sealing rings to make tighter contact with the drum hub. This seemed to improve things but of course was not a real solution. I also sanded the pump plate as it was warped, but it did not improve the pump cross leaks much. I finally watched some YouTube vids of folks air testing other models of transmissions and they seemed to have similar air leaks and were not concerned about them So I threw my hands up and decided to just install the transmission.

I am happy to report that the transmission appears to be operating fine. Shifts through all gears at the appropriate speeds and all is good. I suspect the sealing rings just need atf and conditions that exist when operating to seal well. Not sure about the pump cross leaks but it works so I’m going to stop spending effort worrying about it. Thanks for the replies.

Hope this helps someone else and doesn’t steer them wrong.
Those are a bit leaky. Not being able to actually experience your tests made it difficult to advise you. I'm glad it worked out.