• Hello Guest, we are proud to now have our Wiki online that is completely compiled and written by our members. Feel free to browse our Jeep-CJ Wiki or click on any orange keyword when looking at posts in the forum.

Oil filter bypass valve question

Oil filter bypass valve question

jeepboy45

Old Time Jeeper
Posts
1,239
Thanks
2
Location
Altamonte Springs, Florida
Vehicle(s)
1979 CJ-7, Newly rebuilt AMC 360!, fully rebuilt GM TH400, Quadra-trac TC w/Milemarker 2x4 conversion, AMC mod 20 rear w/1 piece Moser axleshafts, mod 30 front w/tie rod flip and castor correction shims, 4 in lift, Centech complete wiring harness, dual electric fans on 3 core aluminum radiator, tilt steering wheel, 20 gal poly gas tank, new J20 steering box, MSD 6A ignition combined with TeamRush distributor mods
This is becoming a bit of a joke ! And not in the fun kinda way.

I have collected enough AMC parts (pretty much 4 or 5 of every engine part) that I have begun to notice very definite differences.

There is a book called "BJ builds an AMC". Someone recommended it to me, and I bought it. It has some good innovative ideas, but all-in-all not too much different than the technical service manual that I got from the AMC dealer 25 years ago.

There is one part where for initial engine break-in he blocks off the bypass valve to ensure total oil filtration for the initial oil change, then he returns it to normal.

I wasnt going to do his temporary modification, but while I was cleaning the housing, it got me looking at that valve on the housing where the filter screws on.

The one on the left is the one I was going to use. It has absolutely NO blockage, and in theory would allow oil to bypass the filter.

The next one in the picture has what I remembered to be correct. A spring loaded "blockage" that would allow oil to pass when there is enough pressure. (as if someone had a clogged up filter)

The one on the right has a total blockage, actually cast into the metal, with no "springiness", so that it could not allow oil to pass....

WTH????

I assume the one is correct, but ????????????????????

Imput would be greatly appreciated....

(BusaDave and CJ usually cant stand remaining silent !!!) again, WTH??

BCD_4290a.webp
 
Last edited:
I installed a Bulltear filter relocation kit on my 401, and it is made without the bypass. It depends on the bypass in the filter it self. You can get a bypass block from Bulltear. I my self would use the one on the right.
 
BTT..

Anyone else.

I'm leaning towards the one on the right as Purple suggested.
 

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a contribution.

Help support Jeep-CJ.com by making a contribution.
Goal
$200.00
Earned
$0.00
This donation drive ends in
0 hours, 0 minutes, 0 seconds
  0.0%
Back
Top Bottom