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View Full Version : Auto Shut off at 3000 psi, upper piston removal problem.



ybulldog
04-02-2011, 08:38 PM
I received a 4500 psi unit # 397 shoebox on March 29, 2011 . I ran it on an off about 2 hours at a time and rested about 20 minutes between white lithium grease lubing. I cannot fill my 44cf carbon fiber pass 3000 psi. I read the forum and check for leaks and there were leaks on both pistons. I have rebuilt the lower piston per the video. That was easy to do because the 1/8 " high pressure fitting came off. I also adjusted the both belt tensions because there were too tight on arrival. However, I cannot take out the upper piston. The 1/4" high pressure fitting, part #9, is stuck to part #8, the stainless 4500 psi air line. I unloosened the fitting but the hose is like welded to the fitting and will not separate.

Please advise since I do not want to damage the unit. I think it has ran for a total of 8 hours on an off.

Kindly,

Steve

Spektrum
04-03-2011, 03:01 AM
I had this same issue except mine is with the upper tube. The fitting that couples the stainless hose line to the brass adapter was stuck. It took some muscle to get it loose and now I can't get an air tight seal with it reassembled. I don't want to over tighten any thing or strip any threads. I have approx 9 hours or run time on my unit (#361).

ybulldog
04-03-2011, 02:19 PM
Mine is the same issue as yours. I rebuilt the lower tube fine, but the upper will not separate. Fitting and hose is TIGHT! I tried pliers but still cannot separate. The hose is to small to muscle it out and I might risk damaging something else. Even if I managed to separate them like you did, I fear that I will have the same leak as you have now.

Is yours still leaking? or have you fixed it and if so, how?

Steve

TomKaye
04-03-2011, 03:55 PM
First step is to loosen the nut on the other end of the air line. This should allow you to remove the entire piston assembly with the air line still attached. Next with the piston removed, unscrew the fitting from the piston. You now have an air line with the fitting stuck to one end. Find a steel pin that will fit through the end of the fitting and rest up against the stuck air line. Use a small hammer to tap out the air line. Let me know if that works.

Tom

ybulldog
04-03-2011, 07:54 PM
Tom,

Thanks for the information.

I ground down a harbor freight pin and tried to hammer out the stainless hose, but that did not work. There appears to be a bushing stuck in the male fitting; it will turn around with effort but will not detach. It just would not separate; it is frustrating since it is the only thing that is holding me back.

With that, I moved forward and rebuilt the piston. That was easy enough. I moved forward and put the lines back together. Both pistons are without leaks on the rod end. The lower piston is good to go, but the top piston leaks at the hose and fitting. I spent about 30 minutes tightening and rechecking for leaks at that junction over and again, but frustratingly unsuccessful.

I think my only option is to buy a new hose and fitting to correct the issue since I cannot tighten it any more and cannot separate the two.

If you have any more suggestions, I will take them with open arms.

Thanks,

Steve

TomKaye
04-04-2011, 07:11 AM
Email me your shipping addy and we will send you a new air line and fittings no charge. They are off the shelf commercial fittings so I am not sure what is wrong with yours. Sorry for the trouble.

Tom

ybulldog
04-04-2011, 05:03 PM
Tom,

Thank you.

I don't know your email but I posted the information to your visitor's messages. If I contacted you incorrectly, please provide information on how I may contact you via email.

Thanks,

Steve

TomKaye
04-04-2011, 06:49 PM
Send to info@shoeboxcompressor.com

tk

ybulldog
04-04-2011, 06:58 PM
Thank you for the info.

Steve

Spektrum
04-08-2011, 06:25 PM
Found my leak on the upper cylinder fitting. It looks like the pressed fitting on the stainless tube cracked when I removed it. Do I need a new stainless tube with the fittings premounted?

TomKaye
04-08-2011, 08:24 PM
Yes. Send your shipping info with a note that you need a new airline and fittings to info@shoeboxcompressor.com

Tomt

TomKaye
04-09-2011, 12:27 AM
Yes, send shipping info and a note saying you cracked the fitting to info@shoeboxcompressor.com

Tom

jdollar
04-10-2011, 01:02 AM
damn Tom, how are you making any money on these things when you keep sending out free repair parts? and as you may remember, i was also a recipient of your largesse( you sent me upper and lower backcheck valves and spare O rings) when my early run shoebox(#42) developed a leak. all kidding aside, if all American manufacturers followed your example, "Made in America" would still mean exceptional quality AND service!!!!

TomKaye
04-10-2011, 02:38 AM
Well you guys don't know me from Adam. This is a completely new product at a ridiculously low price. I am betting that if I make a good first impression with you all, I won't have to spend the money on advertising. The best thing you can do for me is to get on the internet and tell the world about the product. That will "pay" for your free parts. :)

Thanks,

Tom

ybulldog
04-11-2011, 07:52 PM
Tom,

Thanks for the support. I finally got round to switch out the hose and even after I took out the old ones, I couldn't separate the hose from the fitting. With the new one, I put some white lithium grease around the sleeves before tightening to make sure they do not stick. It just tested with some soapy water and there is no leak.

I will wait a few hours to make sure that everything is dry before lubing it with white lithium and hopefully my 44 CF tank will see 4200 psi from 3000 psi. I will post again when I top of my first carbon fiber.

Thanks again Tom!

Steve

ybulldog
04-12-2011, 06:03 PM
After Tom and the SB team took care of me, I got the unit to run again and filled to 3400 psi. It shut off so I checked for leaks and the lower piston leaked at the rod end. I disassembled and rebuilt the lower piston again and it filled to 3700 psi and it shut off. Checked and there were no leaks so I slide the round piece with the spring (auto shutoff thingamnajiggee) to the right slightly and it filled to 4200 psi.

I don't need it any higher since its a 4500 psi tank.

Up to this point, I have taken it apart over 6 times and replaced orings twice.

Some tips that I have learned.

1) When you receive the unit, you don't need to lube it frequently; every 3-4 hours is good.
2) It will need some time to wear in. Eventually, there will be black crude on the piston rods. Disassemble and clean up the crud because the delrin and/or oring is worn and there will be a leak on the piston side. ((Later lesson, just clean of the crude with ammonia free detergent, dry, inspect for defects, relube and reuse if none found)
3) Once worn in, lube about 2-3 hours and check to make sure that the lube has not emulsified. If it did, you have fluid in the line. Replace the desiccants to resolve.

My piston rods do not get black any more. When it requires lubing, I can see the polish so I brush white lithium on it.

Rating: 4.5 stars

I had some frustration with the machine, but I am glad. I can rebuild the thing in 15-20 minutes now and I doubt that there will be anymore surprises.


Thank you Tom and the SB team!!!

Spektrum
04-15-2011, 01:53 AM
Hey Tom, I got the replacement HP line and attached fittings installed on #361. Did a short test and it seems to be all air tight now. I'll know in about 2 hours for sure, I'm filling my tank for Black Hawk Down this weekend @ D-Day Adventure Park :cool:
Thanks for the help!