MCV QUESTION May 22, 2010 11:27AM
PUT A NEW MVC ON AND HAVE 350 OR SO OF PRESURE. TURN TRACTOR OFF, AND START UP AND BLOWS GASKET ON THE BACK SIDE. THE 1 BETWEEN THE PLATE AND MCV. ONLY DOES AT START UP. CAN RUN 3000 RPMS WHEN IT DONT BLOW WITH NO PROBLEM AND GET 410 OR SO. DONE 2 SO FAR AND AM SICK OF REPLACING GASKETS. THE MCV IS A 86 STYLE. DO I NEED A 06,56,66 STYLE? ANY HELP WOULD BE NICE
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Re: MCV QUESTION May 22, 2010 01:12PM
be sure all surfaces are clean and flat.. torque capscrews to 240 in, lbs. ,,make sure the oil cooler bypass valve is free and working.what port are you taking your readings from?
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Re: MCV QUESTION May 22, 2010 01:30PM
its all clean, mcv hsing is all nos. been in a box for 15-20 yrs. cleaned and resealed it all. taking reading from very top plug.
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Re: MCV QUESTION May 22, 2010 03:05PM
are you using proper o ring and good gaskets
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Re: MCV QUESTION May 23, 2010 03:07AM
yes, all oem
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Re: MCV QUESTION May 23, 2010 06:01AM
check your pressure on the bottom of mcv, disconnect line that goes to hyd. clutch assist and put guage there. no more than 400 psi on high and low side of ta
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Re: MCV QUESTION May 23, 2010 07:55AM
have in past. the guy wanted it above and 400 or more psi.
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Re: MCV QUESTION May 23, 2010 01:13PM
anything over 400 psi most ta's cant hold the pressure and will leak internally. will also leak in the mcv good luck
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Re: MCV QUESTION May 23, 2010 02:13PM
400 is too high to last... u need to put the gauge in the dump valve port,that reads direct pressures in the ta circuits,,,the bottom port will only give u readings in the generall return circuit from power steering, which is factory 185-250 ,tourque is critical 240 in, lbs
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Re: MCV QUESTION May 24, 2010 05:06AM
If you have a warped spacer plate and I mean slightly, check it with a true straight edge, you will not hold the gasket. If someone has grossly overtorqued the valve you may have the whole valve screwed up. these guys are right 400 is too high to last 325 is enough.
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Re: MCV QUESTION May 24, 2010 12:04PM
I have one tractor set at 375psi and the other is at 385psi. Just the way it worked out, blew alot of gaskets trying to get the shims right, seemed the gaskets would pop at about 425psi or so. This has worked fine on two different Allied 5 disks. I always torque the MCV bolts.
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Re: MCV QUESTION May 24, 2010 02:48PM
update.... put on a mcv from a tractor that was working fine for 7 yrs. blew gasket right away. then tried ptting just the small spring in the top port. the 1 that goes inside the other 1. started up and was seeping. had 190 psi. started up again and blew gasket. im thinking its not the mcv. but who knows. any more help would be apreciated. am very puzzled and frustrated.
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Re: MCV QUESTION May 24, 2010 03:31PM
Steering is first priority so maybe relief pressure valve or priority valve is sticking. Ta is the last thing to get oil, so checking ta pressure is end of line when pump builds pressure on start up. I cant remember which plug you take out, seems like about third plug down. check valve for scaring, needs to move freely.
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Re: MCV QUESTION May 24, 2010 04:16PM
do wat floyd said. i know they don't have the good gaskets anymore they are all just material. i guess what you could do is put some 515 loctite on the gasket where it is blowing out. you can get it at your local Case IH dealership. but i think you have something stickin and not relieving like floyd said.
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Re: MCV QUESTION May 25, 2010 08:21AM
UPDATE....TOOK MCV OFF MY TRACTOR AFTER NEW GASKET. PUT BACK ON THE OTHER ONE. WORKS FINE. MCV CANT BE THE PROBLEM I THINK..
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Re: MCV QUESTION May 25, 2010 02:57PM
does it make the one off your problem free tractor blow a gasket when you mount it to the problem tractor?
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Re: MCV QUESTION May 25, 2010 03:34PM
What steering hand pump are you using and what tractor are you working on?
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hey matt May 26, 2010 01:15AM
I assume you have talked to tony about this. I would think he would know. I had this trouble once with my 966 and turned out it wasn't tourqed properly but that doesn't sound like your problem
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Re: hey matt May 26, 2010 03:48AM
YA SULLY, PUT STUDS IN AND ITS WORKING NOW
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Re: MCV QUESTION May 26, 2010 01:16AM
yes, the one off the good one blows a gasket on mine. i put it on the good one and it works fine. its a 1466
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Re: MCV QUESTION May 26, 2010 11:14AM
correction.... gasket blew in this time and not out
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Re: MCV QUESTION May 26, 2010 02:00PM
Should have sold when scrap was up to $250.00 a ton !!!!
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Re: MCV QUESTION May 26, 2010 02:22PM
Are you using gaskets from CaseIH, or an aftermarket gasket? You are using the heavy mounting gasket, correct? Is it blowing the mounting gasket between the MCV & the T/A housing? Since this is on a 14, does it also have the extra sandwitch plate to space the MCV further away from the IPTO driven gear?
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Re: MCV QUESTION May 26, 2010 02:26PM
all are cnh gaskets, its the 1 between mcv and plate. am using thick mounting gasket. its just got the 1 plate. at start up it pegs the 600 lb gauge. blows right away. tried everything, 3 mcv's. none worked. they work on another tractor with no problem.
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Re: MCV QUESTION May 26, 2010 02:47PM
Have you changed steering hand pumps or brake valves recently on the problem tractor?
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Re: MCV QUESTION May 26, 2010 02:55PM
why did you replace the pump in the first place?
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Re: MCV QUESTION May 26, 2010 02:57PM
Resealed brake vale last year n did touch steering pump
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Re: MCV QUESTION May 26, 2010 03:23PM
If you got 600 psi reading at the bottom of the mcv cover, the plug on top right with the two springs must be sticking. Sounds like the pump is dead heading until it blows. May want to pull that valve out and check it. To set the pressure with the new mcv buy an inner spring for a 1566 and cut off one coil. It should your pressure where you need to be. Just wondering does it blow out the "o" ring too?
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Re: MCV QUESTION May 26, 2010 03:48PM
its free, like i said i've tried 3 different complete mcv valves. one night the gasket blew. i quit because was sick of it an wanted to drink beer. next day i replaced the gasket, put it on my dads 806 and worked great. its got to be in the tractor somewhere, but dont know what. kinda sucks when you got a pull on friday night, but thats my luck it seems now. appreciate all the comments and advice.
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Re: MCV QUESTION May 26, 2010 03:59PM
call 1 800 233 0743 ask for Dan. He is a good trouble shooter an ta and mcv problems.
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Re: MCV QUESTION May 26, 2010 03:31PM
Srry typo. Didn't touch steering pump
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Re: MCV QUESTION May 26, 2010 04:56PM
Change the hand pump or loop the lines out of the trans housing. Eliminate the hand pump. Just a thought.
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Re: MCV QUESTION May 27, 2010 01:39AM
I don't think your problem is in the MCV itself, simply because you said you swapped it to other tractors & it worked fine, and you said good working MCV's from other tractors blew gaskets on the problem tractor. Something else in the MCV's hydraulic circuit on the tractor itself is causing the problem. Steering hand pump, steering directional control valve, brake valve, oil cooler, steering cylinder/wet bolster, something else on the tractor is wrong or plugged, causing that pump to dead-head until a gasket blows.
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Re: MCV QUESTION May 27, 2010 01:53PM
finally after 5 days we got it. put on a special mcv valve. 400 psi at idle, 500 at 3000rpms. thanks everyone for your help
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Re: MCV QUESTION May 27, 2010 03:28PM
Glad to hear that you have it going. We have had this issue when using a late '66 or '86 MCV on earlier tractors. If you have to take off the thin plate that sets around the pump, you must trim the dowel pins or you will actually warp the valve slightly and not get a proper crush on the gasket around the dowels.
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