1975 Cherokee 360; oil jetting out of filter

Just inserted a rebuilt 360 into my 75 Jeep Cherokee. Started up
great; except oil jets out of the top of the oil filter at the rate of
about a pint a second. My suspicion is that the oil pressure relief
valve is not opening. What accentuates my suspicion is that the
previous build did not have the valve installed...there was just a
spring in the sleeve where the valve goes.

Is this a known issue? Is it common to not install the bypass valve?
Or, is there something wrong with the cylinder in my oil pump where the
bypass valve sits? Or do you think there's something else wrong
entirely?

Any help is greatly appreciated. Cheers

Hi Kirby,
Very common problem. The relief piston is still in the external
pump assembly, just smashed enough to jam it by a combination of bad
motor mount, and missing spring bump stop that causes the engine to
bottom out on the differential.
http://www.bulltear.com/catalog/prod...fe68b9b8153bf0
God Bless America, Bill O|||||||O
http://www.billhughes.com/

Kirby wrote:
>
> Just inserted a rebuilt 360 into my 75 Jeep Cherokee. Started up
> great; except oil jets out of the top of the oil filter at the rate of
> about a pint a second. My suspicion is that the oil pressure relief
> valve is not opening. What accentuates my suspicion is that the
> previous build did not have the valve installed...there was just a
> spring in the sleeve where the valve goes.
>
> Is this a known issue? Is it common to not install the bypass valve?
> Or, is there something wrong with the cylinder in my oil pump where the
> bypass valve sits? Or do you think there's something else wrong
> entirely?
>
> Any help is greatly appreciated. Cheers

Hi Bill,

Thanks for the help and quick reply. It's much appreciated. I just
wanted verify to make sure I understand: you're suggesting that I
replace the oil pump to oil filter adaptor and install a new bypass
valve and spring because most likely the old plunger is stuck down in
my current oil filter adaptor. Thanks again for the quick advice.

L.W.(Bill) Hughes III wrote:
> Hi Kirby,
> Very common problem. The relief piston is still in the external
> pump assembly, just smashed enough to jam it by a combination of bad
> motor mount, and missing spring bump stop that causes the engine to
> bottom out on the differential.
> http://www.bulltear.com/catalog/prod...fe68b9b8153bf0
> God Bless America, Bill O|||||||O
> http://www.billhughes.com/
>
> Kirby wrote:
> >
> > Just inserted a rebuilt 360 into my 75 Jeep Cherokee. Started up
> > great; except oil jets out of the top of the oil filter at the rate of
> > about a pint a second. My suspicion is that the oil pressure relief
> > valve is not opening. What accentuates my suspicion is that the
> > previous build did not have the valve installed...there was just a
> > spring in the sleeve where the valve goes.
> >
> > Is this a known issue? Is it common to not install the bypass valve?
> > Or, is there something wrong with the cylinder in my oil pump where the
> > bypass valve sits? Or do you think there's something else wrong
> > entirely?
> >
> > Any help is greatly appreciated. Cheers

Is the pressure relief valve a pan dump or a filter bypass valve?

If it isn't installed, it is my belief that the oil pressure will be
almost 0 if it is a pan dump type and 'normal' if it is a filter bypass
valve.

I have only seen this valve used once and that was on a V8 Chevy
engine. The owner had never changed the oil and the filter was
blocked. His pressure spiked to 80 or so, then dropped way down but
kept some, then spiked, etc....

I do not think the bypass valve is there to adjust pressure, only as a
fail-safe for a blocked filter.

I would be suspecting something is blocking the output on the filter or
just you have a bad filter gasket.

The blockage could have been the reason the previous owner pulled the
valve to try and stop the oil bypassing the filter via it's O ring
gasket....

Isn't there some issue with getting the pump gear on the correct side to
the front or the oil pressure goes crazy and/or the cam doesn't get
oiled?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Kirby wrote:
>
> Just inserted a rebuilt 360 into my 75 Jeep Cherokee. Started up
> great; except oil jets out of the top of the oil filter at the rate of
> about a pint a second. My suspicion is that the oil pressure relief
> valve is not opening. What accentuates my suspicion is that the
> previous build did not have the valve installed...there was just a
> spring in the sleeve where the valve goes.
>
> Is this a known issue? Is it common to not install the bypass valve?
> Or, is there something wrong with the cylinder in my oil pump where the
> bypass valve sits? Or do you think there's something else wrong
> entirely?
>
> Any help is greatly appreciated. Cheers

Yup.
God Bless America, Bill O|||||||O
http://www.billhughes.com/

Kirby wrote:
>
> Hi Bill,
>
> Thanks for the help and quick reply. It's much appreciated. I just
> wanted verify to make sure I understand: you're suggesting that I
> replace the oil pump to oil filter adaptor and install a new bypass
> valve and spring because most likely the old plunger is stuck down in
> my current oil filter adaptor. Thanks again for the quick advice.

Kirby wrote:
> Just inserted a rebuilt 360 into my 75 Jeep Cherokee. Started up
> great; except oil jets out of the top of the oil filter at the rate of
> about a pint a second. My suspicion is that the oil pressure relief
> valve is not opening. What accentuates my suspicion is that the
> previous build did not have the valve installed...there was just a
> spring in the sleeve where the valve goes.

Sure you don't have two gaskets stuck in there by accident?
That will sure make a mess.

--
DougW

Problem solved: the old bypass valve plunge was still stuck down in the
filter adaptor. When I put the new one in it was sitting on top of the
old one so that the oil had no where to go once it got into the filter.
Whoops. Runs great now.

Kirby wrote:
> Just inserted a rebuilt 360 into my 75 Jeep Cherokee. Started up
> great; except oil jets out of the top of the oil filter at the rate of
> about a pint a second. My suspicion is that the oil pressure relief
> valve is not opening. What accentuates my suspicion is that the
> previous build did not have the valve installed...there was just a
> spring in the sleeve where the valve goes.
>
> Is this a known issue? Is it common to not install the bypass valve?
> Or, is there something wrong with the cylinder in my oil pump where the
> bypass valve sits? Or do you think there's something else wrong
> entirely?
>
> Any help is greatly appreciated. Cheers

May I ask who 'rebuilt' that engine?

If it was 'professionally' done, well... I would sure be worried about
the quality of that 'rebuild'. Starting up a dry engine will destroy it
in minutes if not seconds.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Kirby wrote:
>
> Problem solved: the old bypass valve plunge was still stuck down in the
> filter adaptor. When I put the new one in it was sitting on top of the
> old one so that the oil had no where to go once it got into the filter.
> Whoops. Runs great now.
>
> Kirby wrote:
> > Just inserted a rebuilt 360 into my 75 Jeep Cherokee. Started up
> > great; except oil jets out of the top of the oil filter at the rate of
> > about a pint a second. My suspicion is that the oil pressure relief
> > valve is not opening. What accentuates my suspicion is that the
> > previous build did not have the valve installed...there was just a
> > spring in the sleeve where the valve goes.
> >
> > Is this a known issue? Is it common to not install the bypass valve?
> > Or, is there something wrong with the cylinder in my oil pump where the
> > bypass valve sits? Or do you think there's something else wrong
> > entirely?
> >
> > Any help is greatly appreciated. Cheers

It would be prudent to replace the filter adaptor, just so your new plunger
can mate with a new bore and experience longer service life.

Earle

"Kirby" > wrote in message
ps.com...
> Problem solved: the old bypass valve plunge was still stuck down in the
> filter adaptor. When I put the new one in it was sitting on top of the
> old one so that the oil had no where to go once it got into the filter.
> Whoops. Runs great now.
>
> Kirby wrote:
> > Just inserted a rebuilt 360 into my 75 Jeep Cherokee. Started up
> > great; except oil jets out of the top of the oil filter at the rate of
> > about a pint a second. My suspicion is that the oil pressure relief
> > valve is not opening. What accentuates my suspicion is that the
> > previous build did not have the valve installed...there was just a
> > spring in the sleeve where the valve goes.
> >
> > Is this a known issue? Is it common to not install the bypass valve?
> > Or, is there something wrong with the cylinder in my oil pump where the
> > bypass valve sits? Or do you think there's something else wrong
> > entirely?
> >
> > Any help is greatly appreciated. Cheers
>

You're lucky the oil filter can didn't blow off fifty miles from no
where. Probably the main reason the V8s have disappeared. Replace the
bump stop on that side.
God Bless America, Bill O|||||||O
http://www.billhughes.com/

Kirby wrote:
>
> Problem solved: the old bypass valve plunge was still stuck down in the
> filter adaptor. When I put the new one in it was sitting on top of the
> old one so that the oil had no where to go once it got into the filter.
> Whoops. Runs great now.