Author Topic: Mac Valve Replacement  (Read 4064 times)

Offline Admiral

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Re: Mac Valve Replacement
« Reply #15 on: October 07, 2014, 01:54:14 PM »
On our challenger III I believe we have issues with the mac valves.

Are the screens / squeegees not coming down right away due to bad mac valves?  Sometimes we will have to keep hitting the print button / reset on the head to get the screen to finally drop then it works fine for the run...

Only an issue on a couple heads but it would be nice to fix it.
A Challanger III does not have Mac valves. The valves are SMC valves. The valves if sticking may of been exposed to air with burnt oil from a compressor. Solution is to change valve on head but find reason for burned oil first. Probably worn compressor seals.

Thanks Rich, will pursue this.

This was an issue with the previous owner.  We are still working on getting the auto as close to 100% as possible.


Offline 244

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Re: Mac Valve Replacement
« Reply #16 on: October 07, 2014, 03:17:02 PM »
On our challenger III I believe we have issues with the mac valves.

Are the screens / squeegees not coming down right away due to bad mac valves?  Sometimes we will have to keep hitting the print button / reset on the head to get the screen to finally drop then it works fine for the run...

Only an issue on a couple heads but it would be nice to fix it.
A Challanger III does not have Mac valves. The valves are SMC valves. The valves if sticking may of been exposed to air with burnt oil from a compressor. Solution is to change valve on head but find reason for burned oil first. Probably worn compressor seals.

Thanks Rich, will pursue this.

This was an issue with the previous owner.  We are still working on getting the auto as close to 100% as possible.
I understand. Buy a couple of the valves on the rear of the heads. They are sticking due to burnt oil in a over worked or worn compressor. The effect is called coking. The burnt oil turns to a tar like substance and the poppet stick in the valve. When its working its fine but when the valve sits non functional for a while the tar prevents the poppet from causing action in the valve. Only solution, replace valve.
Rich Hoffman

Offline Gilligan

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Re: Mac Valve Replacement
« Reply #17 on: October 07, 2014, 03:36:42 PM »
You getting it Gerry?

Offline Prosperi-Tees

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Re: Mac Valve Replacement
« Reply #18 on: October 07, 2014, 05:37:12 PM »
You getting it Gerry?
unfortunately no, I forgot my tools this morning and had to get some paying work done today.