Jacobs Brake Rebuild

[QCDriver]

Could someone with the ability look up the time alloted, in service book, to rebuild an E-Tech E7 Jacobs engine brake?

This should tell me how involved I'll be, doing the rebuild. Thanks.

[rhasler]

Mack Product Improvement Campaign PI0550 paid 1.2 hours, but did not require the same amount of disassembly. I would guess somewhere in the range of 3-4 hours to rebuild both housings and adjust the valve yokes, valves, and engine brake settings if you are reasonably comfortable with making those adjustments.

[QCDriver]

Mack Product Improvement Campaign PI0550 paid 1.2 hours, but did not require the same amount of disassembly. I would guess somewhere in the range of 3-4 hours to rebuild both housings and adjust the valve yokes, valves, and engine brake settings if you are reasonably comfortable with making those adjustments.

Thanks for reply. I thought it would be that time. So I guess it will be about 8hrs for me as I've never done this.

rhasler, can you get any and all info that you can acquire from Mack on this rebuild?

I have the SB for this truck and all info from Jacobs, anything from Mack would be nice. Plus I just like to read all I can pertaining my truck.

Thanks agian for all your help.

[rhasler]

Thanks for reply. I thought it would be that time. So I guess it will be about 8hrs for me as I've never done this.

rhasler, can you get any and all info that you can acquire from Mack on this rebuild?

I have the SB for this truck and all info from Jacobs, anything from Mack would be nice. Plus I just like to read all I can pertaining my truck.

Thanks agian for all your help.

The info from Jacobs Vehicle Systems is all there really is as far as the Jake is concerned. The valve adjustment procedure should be in your owner's manual. Key things to watch for are that you properly torque all fastners, especially the valve yoke (aka the crosshead or valve bridge) to the proper torque. Do not apply torque to the valve yoke nut while on the head unless you hold it still with a wrench (that way the valve stems do not get bent-you definetly don't want that). I would replace the exhaust valve yoke adjusting screws to insure they are the current and much higher quality screws. Update the nuts for the valve yokes to the 142GC242 flange jam nuts and tighten to 33 lb ft. Update the intake valve adjusting screw jam nuts to 142GC243 nuts and torque to 40 lb ft. Do not over torque the exhaust valve adjusting screw jam nuts, tighten them to 40 lb ft. also-if overtightened thay can break/split resulting in excess valve lash when the screw begins to loosen off. Make sure you have the right tools before tearing into the Jake. You need some way to compress the slave piston spring, Jake makes a tool for this, but I can't see spending the money to only use it once or twice. You will also need a small pair of snap ring pliers to remove the snap rings. I would suggest getting the overhaul kit prior to tear down so you can determine which tools you will need to buy/borrow.