I've got to agree with the others here, check the purge valve and the governor. I had a similar problem with the dryer on my Freightliner. It was about time to replace the dessicant cartridge so I did that and rebuilt the purge valve at the same time. The problem of the valve staying open for an extended period got a bit better but never went away. I then started to notice that if I tapped the brakes a few times and made the air pressure drop enough for the governor to allow the compressor to start building air again it would stop. In my case I had also started having issues with the brakes seeming weak when applied. The guage on the dash read equally for both the primary and secondary sides of the system, and the low air buzzer came on around 70 psi, but the brakes still felt weak. When I installed a different guage in the system I found I was only running around 105 psi system pressure, so I jacked it on up to between 125 and 130 where it should have been all along. Now it reads nearly 150 on the dash guage, the low air still goes off around 70, and the purge valve does it's thing without staying open too long like it had been doing.
That said I know on mine the purge valve senses system pressure and cycles based on what the governor is doing. I can't say exactly how it goes about the cycle but, based on my experience, it's cycle time open must have something to do with a pressure differential in the system. In my case, with system pressure too low (at a certain pressure point anyways), it stayed open way to long and would not shut on it's own. However if I made the pressure drop a bit more so the governor kicked in it would close almost immediately when the compressor started pumping and system pressure started to rise.
I know this whole deal about drove me crazy trying to figure out since I was trusting the air guages on the dash to begin with. Once I used a third, known, guage to look at things with a different eye, everything fell into place and I haven't had any more problems out of my braking system as far as the purge valve goes, and the stopping power is now better than it's been since I bought the truck since it's actually running a proper pressure now vs being nearly 20 psi low.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Show Coverage: Central Illinois Strawberry Festival - by Cindy Ladage and Janna Seiz. Every year the coming of summer is highlighted by different events for different people. For some, it is heralded with the end of school, tilling the garden, or completion of the planting season. To us, connoisseurs of find food, antique tractors, farm toys, crafts, and downright fun, the annual Strawberry Festival means summer is here. Every year, in Carlinville, Illinois, the Macoupin County Historical Society and the Macoupin Agricultural Antique Association team up to fill th
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
