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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Jriddle on September 07, 2010, 06:31:26 PM

Title: Aux compressor
Post by: Jriddle on September 07, 2010, 06:31:26 PM
Works better than OEM compressor. I guess I need new OEM compressor. 30 minutes for OEM 15 minutes with aux compressor. Just for you Craig.

John
Title: Re: Aux compressor
Post by: gumpy on September 07, 2010, 06:48:20 PM
Quote from: Jriddle on September 07, 2010, 06:31:26 PM
Works better than OEM compressor. I guess I need new OEM compressor. 30 minutes for OEM 15 minutes with aux compressor. Just for you Craig.

John


::)

Title: Re: Aux compressor
Post by: bevans6 on September 07, 2010, 06:50:25 PM
i got one just like that but my tanks don't detach...  bloody heavy too.    :o

Brian
Title: Re: Aux compressor
Post by: Lin on September 07, 2010, 06:59:26 PM
John,

If your saying it takes 30 minutes to air up with your engine driven compressor, there is a problem.
Title: Re: Aux compressor
Post by: Jriddle on September 07, 2010, 07:26:26 PM
Yep there is a problem. Need good OEM compressor for a MCI/TMC MC-9 with 6V92.

John
Title: Re: Aux compressor
Post by: cody on September 07, 2010, 07:31:08 PM
stir, stir, stir lol
Title: Re: Aux compressor
Post by: Jriddle on September 07, 2010, 07:38:27 PM
Quote from: cody on September 07, 2010, 07:31:08 PM
stir, stir, stir lol

Not today but have in the past?

John
Title: Re: Aux compressor
Post by: RoyJ on September 07, 2010, 09:51:12 PM
I'm a little confused too, do you have one of these driven off your crank:

(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.solware.co.uk%2F2005-images%2Fcompressor.jpg&hash=7184b8a4c78bc6cbc6797647f05208597e1d6fff)

:-[
Title: Re: Aux compressor
Post by: Lin on September 07, 2010, 09:53:26 PM
John,

The best deal on a rebuilt I found was from JR at REI (Rebuilders Enterprise Industry) as I posted somewhere else today (800 489-9860).  They charge more for the core than they do for the compressor but will give you some time to get it back to them before they run the core charge.  They rebuild DD3's also for about half of what I paid for my set.  Although my compressor seemed alright, we changed it when the engine was out in the hope of avoiding having to wrestle with it sometime in the future.  The new one pumps much faster than the old one did.

Roy,

no, on mine the crank does the driving.
Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 06:53:42 AM
Thanks Lin.
I have been looking on EBay and they have a store there. For MCI $335.00 or best offer. Thanks to you I have a number and contact person I will give that angle a try.

John
Title: Re: Aux compressor
Post by: rv_safetyman on September 08, 2010, 06:58:12 AM
John, if that is a Tu-Flo 700, that is a heck of a deal!!!

Jim
Title: Re: Aux compressor
Post by: luvrbus on September 08, 2010, 07:15:13 AM
John, if the compressor doesn't have the Bendix rebuild tag on it I would save my money there are some crappy rebuilt compressors on the market a good one will cost a little more but well worth it IMO


good luck
Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 07:29:08 AM
Thanks all
I will be taking my time on this one.

John
Title: Re: Aux compressor
Post by: cody on September 08, 2010, 07:44:33 AM
On my bus the crank does the driving too, she's afraid to drive it lol.
Title: Re: Aux compressor
Post by: gumpy on September 08, 2010, 08:08:40 AM
Quote from: Jriddle on September 08, 2010, 07:29:08 AM
Thanks all
I will be taking my time on this one.

John

You might want to try cleaning and rebuilding your governor. I had an issue with mine once where it would not air up properly. I eventually cleaned it, greased it, and replaced the o-rings and it
has been working great for 6 or 7 years. The new one I bought to replace it is riding around in the toolbox for a spare.

Usually, one of the signs of a worn out compressor is oil passing through and coming out the dryer discharge. If you don't have that, you might just have a sticky governor. 

Might be worth a try. Certainly cheaper than a new compressor.
Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 08:29:59 AM

My governor will stick everynow and then. Thanks I will give that a try.

John
Title: Re: Aux compressor
Post by: Lin on September 08, 2010, 09:43:45 AM
Duh, thanks Craig for pointing out the obvious that I completely overlooked.
Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 11:07:44 AM
I took off governor and cleaned it. I went to get new o-rings and found Napa sells new one for $12.50. It does not say Bendix all over it but works well. I didn't get a good time to fill from zero but did time 90 psi to 125 psi at idle 8 minutes and at fast idle  3 minutes. The part Number on new governor is H284358.

Cody
I told you no Stir Stir Stir LOL

John
Title: Re: Aux compressor
Post by: bevans6 on September 08, 2010, 11:23:42 AM
Just for reference, and you probably know this already, the normal test for compressor recovery is from 85 psi to 100 psi in no more than 45 seconds, and usually closer to 20 seconds.  That's with the engine at high idle, or 1000 rpm, depending on if you have high idle.  I found some  tests that called for max governed RPN, but I don't think I'm going to stand on the throttle pedal for 20 seconds with a stop watch in my hand watching a pressure gauge...    :P

Brian
Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 01:56:26 PM
Quote from: bevans6 on September 08, 2010, 11:23:42 AM
Just for reference, and you probably know this already, the normal test for compressor recovery is from 85 psi to 100 psi in no more than 45 seconds, and usually closer to 20 seconds.  That's with the engine at high idle, or 1000 rpm, depending on if you have high idle.  I found some  tests that called for max governed RPN, but I don't think I'm going to stand on the throttle pedal for 20 seconds with a stop watch in my hand watching a pressure gauge...    :P

Brian

Alright Brian you p&**%# me off with your test I had to get grease all over me (LOL). I went out and on fast idle it took over a minute to go from 85 psi to 100 psi. Now I had to dig deeper and found the unloader valves sticking. I removed them and cleaned them up now I still am testing them to see if they will stick again. But can go from 85 psi to 100 psi in about 28 seconds on fast idle.

Thanks
John
Title: Re: Aux compressor
Post by: gumpy on September 08, 2010, 01:58:03 PM
So, for us dummies, did you happen to take any photos of the unloader valves and how you cleaned them?

Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 02:00:32 PM
No But still have intake off and can get some.

John
Title: Re: Aux compressor
Post by: bevans6 on September 08, 2010, 02:03:55 PM
Weel - If you think of unloader valve, and your own personal unloader valve, and pictures - do you really think that is a good idea?

28 seconds is right up there in the 'job done, lets watch this and see' category.  It passes the test, it's very close to optimum, but it should not change much from day to day, it should remain pretty consistent.  It's if it starts to change that you start to wonder.

Also, it's important to not have any governor delay time in there.  You need to have the engine running at high idle, you need to make sure that nothing is calling for air, like the door cylinder closing, or the suspension airing up.  Then you fan the brakes down to 80 psi, wait for the governor to cycle, and then measure the time from 85 psi to 100 psi.  You are measuring JUST the compressor recovery that way.

Good job, though, very impressive!

Brian
Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 02:24:31 PM
I removed the intake and the unloader valves are there. Then removed the spring. The top picture shows valves unloaded.
Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 02:27:50 PM
After removing spring I removed the bar that bridges across to the valves. I then found that I had to load the compressor by fanning the brakes to get the valves out.
Title: Re: Aux compressor
Post by: Jriddle on September 08, 2010, 02:29:43 PM
View with valves out and parts on bench. Now I can put it back together

John