The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-31-2024, 07:58 PM   #26
ggalv
Registered User
 
Join Date: Feb 2008
Location: Los Angeles, CA
Posts: 35
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

Here is the latest on my connections to the valve covers. On the passenger side/front, I noticed that the hose was connected to basically a cap (2), I am assuming this is wrong? Can I put the hose on the passenger side (currently on 2) into the opening on the passenger side (1)? Attached are the pictures with (1) and (2) and also show the connections from the carburetor to the valve covers. Thanks
Attached Images
    

Last edited by ggalv; 08-31-2024 at 09:18 PM.
ggalv is offline   Reply With Quote
Old 09-02-2024, 01:44 PM   #27
Willshook
Registered User
 
Join Date: Jun 2019
Location: Chehalis, WA
Posts: 43
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

If that thing on the right is a PCV valve, and it rattles when you shake it, then that's pretty much done.

On the other side, there's no need for whatever the hell that big tube is going to the air cleaner - just plug the holes on that side and be done.
Willshook is offline   Reply With Quote
Old 09-02-2024, 05:49 PM   #28
slikside
Registered User
 
slikside's Avatar
 
Join Date: Jun 2010
Location: San Diego Co.
Posts: 1,176
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

My truck is a '72 C10, not a '70. But...

The hose from the air cleaner riser on mine is on "1". An oil filler plug is in "2". Not sure how critical that is.

P.S. I thought PCVs were supposed to rattle when you shook them?
__________________
1972 Chevy C-10, SWB, Fleet, 350/350, PS, PB, HEI, mostly stock, Survivor.
slikside is offline   Reply With Quote
Old 09-02-2024, 06:02 PM   #29
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,595
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

If a PCV valve rattles when shook, it means the valve is free to move. It doesn't tell you if the valve is seating or if the spring is weak or broken. Spring problems are rare, but PCV valves get coked up all the time.
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 09-02-2024, 07:03 PM   #30
72c20customcamper
Registered User
 
72c20customcamper's Avatar
 
Join Date: Jul 2018
Location: Catskill Mountains,NY
Posts: 8,637
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

Quote:
Originally Posted by Willshook View Post
If that thing on the right is a PCV valve, and it rattles when you shake it, then that's pretty much done.

On the other side, there's no need for whatever the hell that big tube is going to the air cleaner - just plug the holes on that side and be done.
The big tube is to use filtered air for the pcv system air comes in on the passsenger side allowing the gases to be pulled out through the pcv to be burned . You should never plug the breather tubes .
Attached Images
 
__________________
Mark
72 c20 custom camper Husky edition,
66 SS396 Chevelle 1964 Hawk, 63 Avanti,62 lark
1969 AMX ,
1968 c20 stepside ,85 K20
1977 Suburban sold
68 anniversary.
72c20customcamper is offline   Reply With Quote
Old 09-03-2024, 03:05 PM   #31
Willshook
Registered User
 
Join Date: Jun 2019
Location: Chehalis, WA
Posts: 43
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

Quote:
Originally Posted by 72c20customcamper View Post
The big tube is to use filtered air for the pcv system air comes in on the passsenger side allowing the gases to be pulled out through the pcv to be burned . You should never plug the breather tubes .
I don't see the reason for that tube - just put a breather in one of the grommets and the PCV on the other side and call it good.
Willshook is offline   Reply With Quote
Old 09-03-2024, 04:21 PM   #32
slikside
Registered User
 
slikside's Avatar
 
Join Date: Jun 2010
Location: San Diego Co.
Posts: 1,176
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

Quote:
Originally Posted by Steeveedee View Post
If a PCV valve rattles when shook, it means the valve is free to move. It doesn't tell you if the valve is seating or if the spring is weak or broken. Spring problems are rare, but PCV valves get coked up all the time.
So IF it rattles, it MAY be good. But if it doesn't rattle, it's bad. Is that right?
__________________
1972 Chevy C-10, SWB, Fleet, 350/350, PS, PB, HEI, mostly stock, Survivor.
slikside is offline   Reply With Quote
Old 09-03-2024, 05:35 PM   #33
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,595
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

^ Yes.
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 09-04-2024, 12:52 AM   #34
slikside
Registered User
 
slikside's Avatar
 
Join Date: Jun 2010
Location: San Diego Co.
Posts: 1,176
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

Quote:
Originally Posted by Steeveedee View Post
^ Yes.
Cool, thanks.
__________________
1972 Chevy C-10, SWB, Fleet, 350/350, PS, PB, HEI, mostly stock, Survivor.
slikside is offline   Reply With Quote
Old 09-04-2024, 07:31 AM   #35
RustyPile
Registered User
 
RustyPile's Avatar
 
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,809
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

Quote:
Originally Posted by Willshook View Post
I don't see the reason for that tube - just put a breather in one of the grommets and the PCV on the other side and call it good.
I'm not disagreeing with your suggestion, only explaining the components function. The tube is connected to the riser so that it will pick up filtered air.. The part on the other end of that hose is a flame arrestor.. Arrestors disappeared long ago but not the routing concept...
RustyPile is offline   Reply With Quote
Old 09-04-2024, 09:42 AM   #36
PbFut
Senior Member
 
Join Date: Feb 2022
Location: Ca
Posts: 588
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

The 3rd photo on post 26 is of a factory riser, vent hose and flame arrestor. It's path is from the vent hole in valve cover on right side. The PVC valve goes in the left side valve cover hole. A PVC valve is inexpensive and best replaced if in any doubt on condition. Plugged will force crank case blowby up the the opposite side vent tube and grunge up your carburetor. Stuck open will cause a big vacuum leak making hard or impossible starts and bad idle. Plugging the right vent will limit air out of crank case into pvc. I do not know it this is good or bad. The pvc will pull blowby and flowing into intake to be burned is certainly better for pollution. I do not know if it has any power benefit or detriment. Replacing the riser vent tube with a vent cap can be done. Most vent caps don't filter like a engine air filter so there is that to consider.
PbFut is offline   Reply With Quote
Old 09-04-2024, 09:50 AM   #37
72c20customcamper
Registered User
 
72c20customcamper's Avatar
 
Join Date: Jul 2018
Location: Catskill Mountains,NY
Posts: 8,637
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

Quote:
Originally Posted by Willshook View Post
I don't see the reason for that tube - just put a breather in one of the grommets and the PCV on the other side and call it good.
A breather cap will work also the air needs to be filtered . But the current system he has works he just needs to plug the extra hole .
__________________
Mark
72 c20 custom camper Husky edition,
66 SS396 Chevelle 1964 Hawk, 63 Avanti,62 lark
1969 AMX ,
1968 c20 stepside ,85 K20
1977 Suburban sold
68 anniversary.
72c20customcamper is offline   Reply With Quote
Old 09-04-2024, 10:49 AM   #38
PbFut
Senior Member
 
Join Date: Feb 2022
Location: Ca
Posts: 588
Re: 1970 Chevrolet C20 Pickup - Motor Leaking Oil

Yes. I think the extra hole was for a oil fill cap.
PbFut is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:22 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com