Bauer Utilus 1st Run after Overhaul, a Little Help Needed

[wewing1]

I just finished up going through my recently acquired 98 Utilus U3E-H. (this is my first experience operating a high pressure compressor). I replaced all the valves as well as going through the PMV and filter tower, as well as cleaning the inter-cooler lines and a fresh fill of synthetic oil.
After a few short runs to make sure all the fittings and filter tower sealed properly and that the final stage safety valve was blowing off at it's rated 225 bar. (It's final configuration will be set to 330 bar to fill SCBA bottles.) Everything looked fine.
I then connected up to a empty 80cf SCUBA bottle and timed the fill. It took a little under 30 minutes to fill to 3000 psi. Seems a little slow as seems i have read that it should take closer to 20 minutes to fill 80cf.
What really concerns me is that when I shut the compressor down it appears the high pressure in the filter tower is getting past the 3rd stage discharge valve and then flowing back into the crank case, i can hear and feel the air coming out the air filter housing snorkel. The air is also forcing the air out of the sight glass.

Am i thinking correctly that the discharge valve is failing, and that provided there are no other leaks in the system should maintain pressure on the filter tower. If the valve is failing i assume there is nothing one can do other than replace the valve, as it is a sealed unit?

I am getting close to finishing this project up and any help or advice would be greatly appreciated!

 

[wwunder]

I think you will find that the fill time is in the ballpark... The stated fill time of 20 mins probably assumes starting with the filters full already (to OPV) and then filling the Al 80 from 500 psi to 3000 psi. I find the 3rd stage discharge valve isn't perfect and will slowly bleed back to crack case, but it does sound like its leaking back a bit fast. I would probably run a few more fills to see if it sets up better after a bit of use.

 

[wewing1]

Thanks for the feedback. I went ahead and pulled the head and found the discharge valve fouled with what looks like the anti seize compound I used on the suction valve. I learned the hard way that less is better.
Fortunately the valve popped apart when I blew compressed air back through it, so I cleaned it up and will be ready to put it back together later this week

hopefully my refill rate will improve as well

 

[wewing1]

I put everything back together and it it still leaks about 100 lbs per 1/2 hr. I can put my ear up to the 3rd stage discharge valve lock nut on top of the head and hear air movement. I am not sure whether the valve will seat with some use, or is this as good as it gets.
The valve is a Lawrence Factor, maybe a genuine Bauer would seal better?

Opinions, experience, welcome.

 

[Namreg 58]

Either the o ring on the discharge valve isn't seated properly or of the wrong duro.

Worst case scenario is that you may have cracked the head when tightening down the valve cover plate if you didn't back off the stud with the lock nut that sits above the discharge valve.

Pull the valve out and look down the hole for cracks.

 

[wewing1]

Either the o ring on the discharge valve isn't seated properly or of the wrong duro.

Worst case scenario is that you may have cracked the head when tightening down the valve cover plate if you didn't back off the stud with the lock nut that sits above the discharge valve.

Pull the valve out and look down the hole for cracks.

I looked the head over pretty good last night and it looks ok. The o ring is the one that came with the Lawrence Factor valve.

The leak is definitely into the 3rd stage cylinder bore, as there is bubbles in the sight glass and if you put your ear to the intake snorkel you can hear slight oil bubbling. My thinking is the valve isn't sealing at it's seat or where the bottom of the valve seals to the head(metal to metal)

The leak is certainly better than it was before I pulled and cleaned the valve up, but if the goal is to keep pressure on the tower I have a ways to go.

 

[Namreg 58]

Although there is nothing wrong with LF valves or components, if you still have the old Bauer discharge valve, dismantle and clean it up and use it as a test bed to see if it changes anything.

Use a Stanley knife blade in the crack where the valve base separates and tap gently around with a hammer and check the disc and spring moves freely in the housing and also tidy up the seat base on very fine wet and dry paper.

If you are still getting air bubbles in the sight glass, you need to look at the 2 o rings on the piston sleeve assembly.

 

[wewing1]

Although there is nothing wrong with LF valves or components, if you still have the old Bauer discharge valve, dismantle and clean it up and use it as a test bed to see if it changes anything.

Use a Stanley knife blade in the crack where the valve base separates and tap gently around with a hammer and check the disc and spring moves freely in the housing and also tidy up the seat base on very fine wet and dry paper.

If you are still getting air bubbles in the sight glass, you need to look at the 2 o rings on the piston sleeve assembly.

Great idea on using the old valve. I will take a look at it and give it a try if it is salvageable.

You got me to thinking about the the o-rings on the piston sleeve. Wouldn't the leaking air be traveling between the piston and sleeve and find it's way into the direct oil feed hole in the side of the sleeve? The two o-rings are to contain the oil and direct/contain it to the sleeves oil feed hole(s)? Which makes me wonder why the air wouldn't simply take the path of least resistance and flow out the bottom of the sleeve's bore, seems a whole lot easier than forcing itself through the oil regulator into the sight glass? I haven't tore the compressor down that far so I don't know for sure how everything seals up

Update: I took the old one apart as you described(method recommended worked like a champ) and it didn't look to bad. I carefully polished the sealing surfaces with a oil stone and they cleaned up pretty well. I will install it tomorrow and give it a try.

 

[Namreg 58]

If the air was leaking between the floating piston and sleeve, it would be well past its use by date. To test this, pull the floating piston up about 1.5" with a magnet and it should take more than 10 seconds to sink back down again.

 

[NAM001]

I just got my capitano rebuilt with LAWRENCE FACTOR PARTS. I then found out that the parts I bought was not bauer parts. Apparently as I was told after finding out I had a HIgh leak by 1.5 cu ft ((( normally about 1/2 that))) at 3000# the reason is that,,, the rings used were from a vespa scooter of something like that and are sold by LF because they the bought 10k sets and are the same size and supposedly same specs with in tollerance that bauer uses. I am getting about 5 cuft at 3000# and about 4.5 cu ft or better at 4000 psi. I accept that. the parts were half price compared to bauer's prices.

And the third stage was perhaps a 1/1000th different than the bauer part.