American Bristol problems

[frogman62]

Wes,
If you have a leak between the 3rd and 4th stage it will be at the fittings and a little soap and water will show the leak.
If the third stage relief valve #142 is popping off , the 4th stage inlet valve is leaking which increases the third stage pressure causing the pop off. To correct this problem will require removal of at least the 4th stage head. I find it is easier to work on the 4th stage by removing the entire 4 th stage from the compressor since reassembly is a little trickey when still attached.
Before you start any disassembly, YES back pressure , using a 3000 psi scuba cylinder connected to the 4th stage outlet and check for leaks.

I have used a 3/8 fine thread flare fitting (brass) from the hardware store and made a
fitting to connect 1/8 copper tubing which goes to a fitting on the pressure gauge. Don't have the pressure gauges hard connected to the compressor as the vibration will eventually ruin the gauge.
After you have checked the items above -- send results and then I provide some more info
Good luck,

Jim Shelden



What is the best way for me to inspect/test everything? I understand there is this stuff called snoop that helps find leaks in pneumatic systems. Is there another method you recommend.

I can't seem to find an external leak between the 3rd and 4th stage, however will look again this weekend. However the 3rd Stage Safety Valve is popping, I think that's what you mean when you say "Is the pressure relief valve at the inlet of the 4thstage popping off?" If that's not what you mean, please reference the part in the diagram in the manual so I can find it without getting confused

When you say back pressure does that mean you want me to hook up a 3000psi scuba tank to the output on the compressor and turn on the air and listen for a leak?

Is it safe for me to take off the entire 4th stage cylinder head and inspect it for damage or will I be damaging something in the process. If it's something I can do myself I'll tear it down this weekend and send pictures that may mean more to you than to me.

I looked up the 3 way "L" fitting in the manual, which I should have done prior to giving you incomplete information. It is the "Stem Tee Connector" item #84 in the diagrams in the manual and part number Y19502. It has a fitting that seems to match up pretty well with a 3/8" fine thread flare fitting at a hardware store. I was hoping you could let me know exactly what kind of fitting (JIC?, Flare, etc) it is so I could find a way to convert it to a 1/4" female pipe thread so I can hookup a gauge.

Sorry you have to do so much hand holding, I just don't want to do something that completely mangles the whole system. I'm pretty capable when it comes to dismantling and reassembling, I just don't want to get ahead of myself.

Thanks again for all you guidance.

Wes[/QUOTE]

 

[wesval]

Jim - Thanks for the feedback.

I played with the compressor again today. I back pressured the output. It seems like I have a reverse leak with as little as 1000psi. It's really slight down around 1500 but I can hear air leaking.

I took off the intake filter housing cover and the filter and when I put my finger over the intake hole the leaking stops for a second until the pressure builds up and blows past my finger.

So, it almost seems like I have a really bad 4th stage intake valve, no? I figure I should take the whole 4th stage off and start inspecting it. Yes?

Also, I find that there is a copper tube that comes off the crank case cover. In the manual it looks like there should be a pressure plug there, Part #Y11977, #182 on the schematic. The tube is in an upside down "U" shape and it doesn't have any where to connect to. I think it to one of the pieces that the compressor was shipped with, I believe you said I could remove the piece. Regardless, when I back pressure the compressor air comes out there at the same time it comes out of the air intake. If I put my finger over the copper tube that air comes out of the intake more and vica versa. If I put my finger over both, the air builds and blows my finger off the hole.

Hope this helps, hope you can help. Thanks.

Wes

 

[frogman62]

Wes,
If air is able to get into the crank case from the 4th stage outlet, There are several things wrong with the 4th stage.
But I want to clear up a couple of items before we go further.
When you had the compressor running,
did you say the 1st stage pressure was about 50 psi,
the second about 300
and the 3rd about 1200?
If the answer is yes -- then go ahead and remove the 4th stage cylinder and head completely, Disconnect the tubing into the head which connects to p/n 157 in Figure 6.2 Then remove p/n 139 and everything with it by removing the 4 bolts p/n 140.
When you finish that task , then we need to talk on the phone because the next steps are complicated.
From what you have described the forth stage is completely shot.
Jim

 

[Batt]

Hello Wes and Jim,

I have been tied up with a sudden divorce and crazy stuff for the last few months, and getting back to work on my compressor again. I think it has a similar problem to what Wes mentioned, so I'll start with trying to test each stage.

Just wondering, if Wes's compressor turned out to have a bad 4th stage or how that went?

Thanks
Avi

 

[wesval]

Avi and Jim -

After talking with Jim on the phone in early November I found that my 3rd stage seemed to be in decent shape. Then we looked at the 4th stage piston and found that it too seemed to be holding air which was also encouraging.

Jim then told me to look at the 3rd stage exhaust valve which was sure enough stuck in place and wasn't budging. I smacked it out with a block of wood and a plastic mallet. I cleaned then entire 4th stage with WD-40 and blew air through the inlet valves. I worked out pretty well and didn't take much time.

I then went to put everything back together and did it a couple times to make sure I did it right. I used a 1" spackle knife to hold the spring in the cylinder head during reassembly. Then I started it up with high hopes and it started leaking air around 1100psi.

I was crushed, then I got busy for a couple weeks, today I took off the head again and put it all back together. I went back together the same way it had been before, so I figured I would tweak the head bolts a little more than recommended in the manual, started it up and IT WORKED!

So I tested the pressure and got it to push a full 5000psi, I was so excited. I bought this freaking thing in JUNE and just got it working today!

With that said, I lucked out with my purchase there were some days there when I thought it was never going to work but sure enough with a little work, a new motor and some very helpful guidance I'm in good shape.

 

[wesval]

Jim - After getting the compressor up and running I ran it on an old SCBA 4500 tank and filled it up to 4500, after unhooking the tank I noticed a little sputter in the air flow from the compressor. The air flow never stopped but it did seem to hesitate then spike for just an instant. I thought one time I felt a little piece of something hit my hand, but it was cold outside and I could have been imagining things.

So my question is, since I saw some debris in the inlet valve when I took it apart when we were on the phone should I take the head apart again and blow air through the valve to clear out any new material?

Also, is this problem just because the compressor hasn't been run at high pressure for months? or is it indicative of a more severe problem, is there a way I can avoid it etc?

Lastly, I am just filling paintball tanks, never breathing, should I have any kind of filter on the end air or could I just save money by filling right off the compressor? Also, I ran the compressor for about 5-10 minutes with no load after filling the tank to 4500psi, is there something different you recommend as a cool down process, I can't imagine that shutting it off after pushing it to 4500psi is a good idea, any ideas?

Thanks again for all your help.

Wes
wesval@yahoo.com

 

[pescador775]

You will need a coalescer tank with drain valve to collect moisture. Otherwise, it will end up in the tank. No need to "cool down" a compressor. Usually, they don't run very hot. After all, there is no internal combustion. However, running at no load for 10 secs will clear out droplets of water in the fourth stage.

 

[frogman62]

Wes, Pesky is correct -- 10-15 SECONDS is sufficient not 10 minutes
I have a 5000 psi military moisture trap with a canister cartridge that can be repacked that is suitable for paint ball applications. Price with dessicant cartridge is $120 plus shipping
Jim

 

[Steve Tuttle]

Hi, I'm Steve and have similar problems with the 4th stage, can't find a manual so I'm open for what ou have if you haven't sold it yet. I think the valve plate is the real problem and it's so critical that it mates correctly, and I don't know the configuration of the four spring wishers. I was wondering if you could help me? If I get a copy of the manual I'd be glad to make some copies for you as well. sltuttle@wildblue.net Thanks Steve

 

[PBNZ]

hi guys
we have allso recently bought the duplex 4 stage witch we converted to run via 1100cc 3 cylinder subaru motor as this is a paintball compressor and needed to be portable unfortunatly recently half way through our 2 day event the compressor deciced the only thing to do was dump all air out the dump drain and still dose we have sent the pressure balance valve away to be seviced and have had that back but still no luck all pressures across the 4 stages are in there limits although there was a large build up off carbin in the 3rd stage outlet witch we have cleand dose any one have a manul or bette still is there any place to download a pdf manual off the bristol duplex 4s.24.50 as this would be very helpfull as we are based in new zealand and shipping is a killer
cheers herb