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Doug Barnowski
Doug Barnowski,
Category: Medium and Heavy Trucks
Satisfied Customers: 6
Experience:  HD Truck Mechanic at VIP Truck Center, LLC
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I have a 2010 Mack with a MP8. There is not enough clearance

Customer Question

I have a 2010 Mack with a MP8. There is not enough clearance to adjust the valves
JA: What's the make/model/year of your truck? Engine type?
Customer: What's the make/model/year of your truck? Engine type?
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Heavy Truck Mechanic I'm going to connect you with knows all the tricks and shortcuts. Are you fixing your truck yourself? What have you tried so far?
Customer: yes, in our shop
JA: Anything else you want the truck mechanic to know before I connect you?
Customer: no other then we just can't adjust the valves because the shims are too thick and the valves are beating into the valve seats
Submitted: 4 months ago.
Category: Medium and Heavy Trucks
Customer: replied 4 months ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 4 months ago.
I have 8 of these trucks and am wondering if this is going to be an issue with all of them
Expert:  Doug Barnowski replied 4 months ago.

Hi, my name is Doug.

So it sounds like you are adjusting the Exhaust valves, is that correct?

First you have to bleed the oil out of the exhaust rocker arm by putting inside of the little hole on top of the rocker arm a small 90 degree bent pick and hooking the spring and pulling outward and at the same time pushing down real hard on the end of the rocker's valve end. This will bleed the oil out of the e-brake piston that is inside.

Next when you put the feeler gage in between the bridge and rocker arm, if it doesn't go you remove the shim and get a thinner one and install it into rocker and try and install the feeler gage. if is too loose get a slightly thicker shim until the feeler gage just fits snugly.

It's a trial and error process. Figure about 3-4 hours to run the complete over head and install the valve cover and air cleaner.

I hope this helps and please rate my help for today, thanks.