TH400 Vacuum Modulator Change
Thread Starter
2nd Gear
Joined: Aug 2006
Posts: 2
Likes: 0
TH400 Vacuum Modulator Change
Hi All,
Would like some info from anyone who has expereince changing the vacuum modulator on a TH400. The current unit in my '68 has developed a leak in the crimp area and is making a mess on the exhaust (not to mention a trail of smoke behind the car), so I have bought a replacement unit. I have instructions on how to replace the unit itself (looks pretty simple), but I have a question about the ATF already in the transmission. I only plan to replace the vacuum canister itself, not the valve behind it. I don't have any prior experience with this, so my question is....do I need to drain the ATF level down below the trans modulator hole to avoid a big mess with fluid flowing out the hole, or will the the valve prevent the ATF from leaking out while I switch out the module can?
Thanks!
Would like some info from anyone who has expereince changing the vacuum modulator on a TH400. The current unit in my '68 has developed a leak in the crimp area and is making a mess on the exhaust (not to mention a trail of smoke behind the car), so I have bought a replacement unit. I have instructions on how to replace the unit itself (looks pretty simple), but I have a question about the ATF already in the transmission. I only plan to replace the vacuum canister itself, not the valve behind it. I don't have any prior experience with this, so my question is....do I need to drain the ATF level down below the trans modulator hole to avoid a big mess with fluid flowing out the hole, or will the the valve prevent the ATF from leaking out while I switch out the module can?
Thanks!
Safety Car
Joined: Oct 2004
Posts: 3,923
Likes: 733
From: Youngstown Ohio
No, you don't have to drain the fluid.....there may be some slight leakage, but you will be able to replace the module without getting messy. I changed mine some years ago and had no mess issues.
Le Mans Master
Joined: Aug 2003
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From: Chattanooga TN
Team Owner
Joined: Jun 2000
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From: Southbound
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Safety Car
Joined: Oct 2004
Posts: 3,923
Likes: 733
From: Youngstown Ohio
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