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Topic: Air Dryer Bypass Demo (Read 12625 times) previous topic - next topic

Re: Air Dryer Bypass Demo

Reply #20 –
Bill, now I know what to do with the scrap pvc! Thanks, always used conduit, this is lighter ^.^d

Re: Air Dryer Bypass Demo

Reply #22 –
Quote from: Dick S –
Roger's set only goes up to 1 5/8" though. Would that be big enough?

I think you may find fittings bigger than 1 5/8" on your coach - only way to be sure is to crawl under there and look.  As for the cheater pipe, it must be just big enough to fit over the "non-working" end of the wrench, but not too big or it will slip off and you'll hurt yourself.  Buy the wrench set, then scrounge up the cheater pipe that fits.

Re: Air Dryer Bypass Demo

Reply #23 –
Someone who is an expert,  please correct me if I got this wrong...

My understanding is that you should never use Teflon tape on other than water pick especially,  as a Teflon fragment getting away can cause a world of grief.

Thai being true (?),  what,  if anything,  should be used to seal the threads?

Re: Air Dryer Bypass Demo

Reply #24 –
Thanks, I'll go for the larger sizes. ;)

Re: Air Dryer Bypass Demo

Reply #25 –
Does anyone have the part number for the control line flare plug?

Re: Air Dryer Bypass Demo

Reply #26 –
I'm trying to get the pieces together,  but without access to my coach for a couple of weeks.

Just what are the wrench sizes needed for the two large hoses?

Re: Air Dryer Bypass Demo

Reply #27 –
If I remember correctly (it was five days ago after all ::) ), 1 ⅛" on our coach. If you need to take the connecting block off on the input side (which has the line going to the wet tank and the line going to the governor as well as the hose, that was 1 ¼".

Quote
I'm trying to get the pieces together,  but without access to my coach for a couple of weeks. Just what are the wrench sizes needed for the two large hoses?

Re: Air Dryer Bypass Demo

Reply #28 –
Tom, only use pipe tape or pipe dope on NPT ( national pipe thread) If you use the tape, leave the first two to three threads bare. That would go for the dope also. JIC fittings are self sealing

  Richard B
 

Re: Air Dryer Bypass Demo

Reply #29 –
Tom,

I will be back under my coach tomorrow morning.  I'll take some measurements of the various hose end fittings and get back to you on the wrench sizes.  As for the flare plug, it would be good to have several different sizes:  perhaps 1/4", 3/8", and 1/2".  Never know when you might want to plug off a air line somewhere on your coach.

Re: Air Dryer Bypass Demo

Reply #30 –
Chuck, would be nice to have ALL the wrenches a person might use, but hate buying a set of 15 or so just to use one or two. With the hex wrench having a very narrow head, and you having used them, you know how they can get into some very tight places.

 Richard B

Re: Air Dryer Bypass Demo

Reply #31 –
Quote from: rbark –
Tom, only use pipe tape or pipe dope on NPT ( national pipe thread) If you use the tape, leave the first two to three threads bare. That would go for the dope also. JIC fittings are self sealing

  Richard B
 

That is what I figured.  I was hoping you would chime in on this.

I also figured leaving the threads bare would be plenty good enough for this purpose.

(and I thought NPT was New Process Technology, oh well)

Thanks,  Tom

Re: Air Dryer Bypass Demo

Reply #32 –
Actually, Plan "A" is to service or replace with factory reman the dryer every two to three years.  Will substantially reduce the likelihood of dryer failure.

Plan "B" is a good fall-back position, but Plan "A" is preferred.

Re: Air Dryer Bypass Demo

Reply #33 –
Brett, + one on that!

Re: Air Dryer Bypass Demo

Reply #34 –
I'm in, with both plan A and plan B.

I had my air dryer completely rebuilt six months ago, and just bought the parts for the bypass kit on eBay.

Re: Air Dryer Bypass Demo

Reply #36 –
If you buy the "really big wrenches"™ from Harbor Freight you can use the one of the other wrenches as a cheater bar. If you can get the box end of the wrench on you can wedge the box end of another wrench on the open end of the wrench. If you can only get the open end of the wrench on you can use the box end of another bigger wrench over the box end. I've only had one bolt I couldn't get off using this method and that one came off with the addition of PB Blaster and some heat.

Hope that makes sense!

see ya
ken

Re: Air Dryer Bypass Demo

Reply #37 –
Isn't it possible to keep the D2 governor in the system with the air dryer bypass?  Maybe have a small hose fitting on the bypass so the governor stays, to open the compressor output when max or to restart compressing when min psi is sensed.

Our air dryer has a brass valve fitting on one port that has several hoses. I think it is needed to keep from pulling oil from compressor. This valve would need to be part of the bypass to protect the compressor.

Re: Air Dryer Bypass Demo

Reply #38 –
Barry,
D2 Governor has 3 unloader ports.
1 for air dryer
1 for compressor intake valves unloader
1 not used (at least the way mine is plumbed)
Stopping the control signal air leaking to the air dryer (after "control" flexible tubing has been removed) is necessary in order for the governor piston to fully complete its travel.  That will allow the control signal outlet pressure to build and send the high pressure control signal to the engine compressor intake valves unloader.  That unloads the compressor allowing bypass flow until the governor low press setpoint (wet tank pressure) is reached and the cycle starts over again.
Neal

Re: Air Dryer Bypass Demo

Reply #39 –
Dan, you can get the parts from Billy Jack, I did about two months ago when this topic began.  I guess cheaper elsewhere but getting direct from FOT I though I would get the right fittings.  So is you heading to Nac soon, that one option

mike