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| | | Forums66 Topics128,068 Posts1,055,883 Members48,428 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Apr 2009 Posts: 232 Shop Shark | | Shop Shark Joined: Apr 2009 Posts: 232 | I have a freshly rebuilt 58 235 in my 54 1/2 ton. I seems to be making a lot of oil pressure. I hooked up a second guage and am getting the same readings.After running for an hour drive in 100 degree heat I still get nothing less than 25 at idle and 45-50lbs. at cruising speed. I'm using 10-30w oil and a zinc additive. I know good pressure is better than not enough the problem is with leaks. I get a hand sized puddle in the garage an hour after it's parked. I can't tell exactly where the leak is yet. Seems to drip from the hole in the inspection cover on the bell housing. Could be pushing out the rear pan gasket, rear main, or at worst the rear galley plug. oh and yes it is a new oil pump with the rebuild. Crank bearings specked out good with the plastiguage during assembly.Engine runs great just not sure if I should pull the pump and see if there is a problem with the relief spring or not. thanks for any advice. | | | | | Joined: Oct 2009 Posts: 35 Shop Shark | | Shop Shark Joined: Oct 2009 Posts: 35 | im having the same thing going on with my 53 3100 and at times my oil pressure will spike to 75-80 psi. the most annoying thing of all is the darn mess it leaves when parked in the garage. until i saw your post i just thought my drain plug was stripped since it seems to be dripping there. it dosent take much oil to make a big mess | | | | | Joined: Apr 2010 Posts: 283 Shop Shark | | Shop Shark Joined: Apr 2010 Posts: 283 | Neswes, If I had your oil pressure situation I would be very happy.That sounds to me like a good tight set of bearings and probably the pump was speced as a high pressure possibly high volume item. I think your leaks are not related to oil pressure but to sealing problems.In my opinion increased oil pressure should not make the gaskets and seals any more likely to leak. Any leaks increased by a rise of oil pressure would be internal and would just drain back to the sump. The pan gasket and the rear shaft seal are never required to handle pressurized oil so not effected by a pressure increase and crankcase pressure should be uneffected by oil pressure increase. Look to proper sealing of oil pan, rear shaft seal, and possibly welch plug at the rear of camshaft and I think your leak can be eliminated.
Bob Taylor
| | | | | Joined: Feb 2006 Posts: 549 Shop Shark | | Shop Shark Joined: Feb 2006 Posts: 549 | | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | I wouldn't say that your oil pressure is too high and as was stated, oil pressure is generally not related to leaks. The oil dripping out of the inspection pan is most likely from the rear main. One thing that you could do is install a PCV system. This seems to help alot with leaks. | | | | | Joined: Apr 2009 Posts: 232 Shop Shark | | Shop Shark Joined: Apr 2009 Posts: 232 | thanks for the replies. I forgot to mention that I have the stock road draft tube and a twist on valve cover breather.I guess I'll probably end up pulling the pan and see if I can determine exactly where the leak is coming from | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | If you remove the clutch inspection cover, you may be able to see a trail of oil on the flywheel. That is the tell tale sign of a rear main seal leak.
Did you install a rope seal or a neoprene seal? | | | | | Joined: Apr 2009 Posts: 232 Shop Shark | | Shop Shark Joined: Apr 2009 Posts: 232 | It's a neopreme seal. I'll pull the clutch cover and check for the oil trail on the flywheel. Sure hope it's not the rear main, that'll be tough to change. | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | People have a lot of trouble trying to get the rear main to stop leaking. It basically is there to stop oil from running out on the crankshaft. The area is supplied with oil as the rear bearing sheds oil out both sides. The reason that a PCV system can make s difference is that it creates a negative pressure atmosphere within the motor and thus the oil doesn't run out as easily. | | |
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