83 mc9 cooling fan air ram question
 

83 mc9 cooling fan air ram question

Started by tombuchanan, March 20, 2021, 02:12:10 PM

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tombuchanan

I started my mc9 for the first time since rebuilding the air ram that tightens the cooling fan belt and noticed that as air pressure started to build the ram pulled in loosening the belt.  Is this normal at low engine temps or did I put it together backwards?  I didn't want to to keep running it and see what happens when the engine is warm as i'm afraid the belt would come off being this loose.

Raymond smith

Sounds like you have the hoses reversed.
1957 4104-3632 & 1989 mci 102c3

If it doesn`t fit properly the first time, Get a bigger hammer

tombuchanan

that was my first thought, but i thought maybe it was designed to loosen the belt on startup so the engine warmed up faster then switched to tighten when it was warm enough

tombuchanan

i switched the hoses around and there's no way that's the way it was based on how awkward they have to bent.  I also replaced the air valve at the same time so maybe that's where i messed up.  i have the air supply coming in the top of the valve, the right goes to the regulator, and the left to the ram front.

Busted Knuckle

I don't remember if that vintage MCI did or not, but a lot of the valves were a dual action where in one position they pushed out the cylinder and in the other position they sucked the cylinder in to make it easier to change the belts.
;D  BK  ;D
Busted Knuckle aka Bryce Gaston
KY Lakeside Travel's Busted Knuckle Garage
Huntingdon, TN 12 minutes N of I-40 @ exit 108
www.kylakesidetravel.net

;D Keep SMILING it makes people wonder what yer up to! ;D (at least thats what momma always told me! ;D)

buswarrior

WhatBK said.

It sucks in to change the belt, pushes out for normal operation.

Valve in opposite position, or the lines to the valve are in wrong holes?

Nice to hear someone fixing the useful stock tensioner, and not just replacing it with a fixed bar.

Happy coaching!
Buswarrior
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

tombuchanan

in one position my valve loosens the belt and in the other it dumps air out one of the open valve holes which i guess is for loosening the belt.  so i guess i messed up when replacing the valve.  as for fixing it, if i had known i could get away with a straight bar, i would have gone with that since i'm in more than 200 on the fix so far.

buswarrior

Try changing that belt with the @$# of the bus hanging in the active lane in the rain...

Every penny of returning the ram to operation will be well spent, you'll have the new belt on in about 10 seconds...

lesson taught to the crowd, mark everything for re-assembly!

Good job!

Happy coaching!
Buswarrior
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift