Oil leak from bottom of oil dipstick tube

[bigblue92]

1992 K1500 5.7L (TBI)

I unbolted the oil dipstick tube from the head to do head gaskets, bolted it back up, and it's now leaking from where the groove/bump on the tube is supposed to sit in the block. I'm unsure where I should go from here.

I first thought it was a pcv valve, because I did wind up cracking the plastic on the valve, so I replaced it along with the line, but even after replacing it, it still leaks.

Any insights would be appreciated

 

[Wolvrine82]

I don't know if those have an o-ring, but if not I know we use green loctite on twin cylinder briggs and stratton dipstick tubes and it works really well.

 

[bigblue92]

I don't think they do have an o-ring. I didn't see one when I originally pulled it out, but my boss (I work at a small garage) suggested to do that, and use back gasket maker (black RTV) to try to create a seal. If that doesn't work, I'll consider the green loctite

 

[Komet]

My vote would be a light schmoo of ultra black (oil control) RTV.

 

[bigblue92]

My vote would be a light schmoo of ultra black (oil control) RTV.

I just did that about a half hour ago, I'm going to start it up tonight (maybe 3 to 4 hours from now) and see what happens

 

[Komet]

I like to give it a 24hr cure but the stakes are pretty low here.

 

[Schurkey]

1992 K1500 5.7L (TBI)

I unbolted the oil dipstick tube from the head to do head gaskets, bolted it back up, and it's now leaking...

...I first thought it was a pcv valve, because I did wind up cracking the plastic on the valve, so I replaced it along with the line

1. Did the dipstick tube get bent in the process?

2. Is the PCV system WORKING? No pressure build-up in the crankcase?

3. 1997 C/K service manual page 6A-246 specifies GM "Teflon" sealant 12346004. Locktite/Permatex 592 is the equivalent.

 

[bigblue92]

1. Did the dipstick tube get bent in the process?

2. Is the PCV system WORKING? No pressure build-up in the crankcase?

3. 1997 C/K service manual page 6A-246 specifies GM "Teflon" sealant 12346004. Locktite/Permatex 592 is the equivalent.

I'm not sure if the dipstick tube got bent, I can't remember.

I replaced the PCV valve and line going from the valve to the TB yesterday. The old one was all gunked up.

I used some ultra black permatex, I'm going to start the truck up sometime after work

 

[Schurkey]

I replaced the PCV valve and line going from the valve to the TB yesterday. The old one was all gunked up.

Is there light vacuum at the air cleaner spacer side of the system when the vehicle is idling?

 

[bigblue92]

Is there light vacuum at the air cleaner spacer side of the system when the vehicle is idling?

The is no vacuum coming from the air spacer cleaner