I've been reading online about guys having issues with their oil pressure relief valves sticking on the 700s and 800s. The previous owner blew out an oil seal and ran it out of oil. I've been putting a few hours on it now and have some oil leaking from a few different seals (oil filter seal and the pressure relief hose on top of the valve cover), so I decided I should check the pressure relief valve.

I took the bolt and the spring out. I tried to get the dowel out with a magnet and it didn't come out, so I placed a rag over the hole and started the machine and expected the dowel to come shooting out of there but it didn't move. I've read several other people online having it stuck in there so hard that they actually had to take the oil pump out and push it out from the bottom.

What I can't figure out is every once in a while when I try to start it, especially if it dies when the engine is cold, when I crank it over, it sounds like it has no compression. It will do that over and over until I just let it sit for a few minutes, then it will start and run no problem. I assumed this was from the pressure relief valve stuck open and not allowing the lifters to build up pressure... but now I find the valve is stuck closed, so that doesn't make sense to me?

Machine is an 05 Ranger 700XP.

Is the valve stuck down? Why the lack of compression thing sometimes? I'll try soaking it with penetrating oil for a few days and seeing if I can get it out, but I'm assuming my next step after that is to take the mag and flywheel off and that side cover and take the oil pump out... right?

Thank you again OPT.

 

Yes they can get residue in the valve chamber,gall up and stick. I soak it with PB blaster or Liquid Wrench first for a couple days.You can get to the oil pump easy enough with out splitting the cases,but I can't remember off hand if the valve is easily accessed or not with the oil pump out.Guess I've been lucky all these years and only had to fight one,but got it out after soaking.Plus having a good strong telescoping magnet that you can work up and down helps on pulling them out.

 

Sounds good. I'll soak it for a few days!

Can you explain the lack of compression thing while starting it if the valve is stuck down? (I'm just curious how it works).

 

See if this helps..https://www.sxsnation.com/forum/thre...e-thread.1682/

 

That answers all my questions! Thank you again!!

 

Gave it another shot of PB Blaster every couple hours, and it was moving a little but so I kept working it back and fourth with a punch and starting the engine, and I finally got it to shoot out of there.

I was expecting to see some markings and aluminum residue and stuff on the side of the dowel, but it looked pretty much spotless. I still polished it up with some 1500 grit sandpaper, but before I put it back together, is there any way I can clean up the inside of that hole, or should I be good to go now that its broken loose?

 

I would like to say a small bore brush,but that may not help matters.600,800 grit wrapped tight on a pencil might help a little. Like the other post mentioned it's a shame that the bore wasn't steel or chrome lined and that would solve a lot of the problem. Other than cleaning the relief valve plunger every 6 months or so,that's my best recommendation. Remember to do this at every oil and filter change and you shouldn't have future problems.