I fully agree, the dealer/technician bashing gets a little old. The old parts will tell the story. If I put on every thread of incompetent things I have seen drivers do I think it would crash the TTR server. Most all my dealings with the dealers I frequent is honest, pleasant, and helpful experience. With over fifty trucks, they tend to treat their repeat customers well.
changing head gasket on paccar mx13 epa 10... help!!!
Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by splittero1, Feb 25, 2020.
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26 M18 bolts and 7 M12 bolts, rocker bolts are 4 seperate bolts around perimeter of rocker assy. Yes, you need to back head bolts of in sequence to prevent warpage. I would pull injectors before removing head and put in sealed clean Ziploc bag. Keep everything in order down to the bridges on exact same valve. Get a good paint marker. Get something clean to cap the EUP's and flush them by operating the hand primer pump before installing fuel pipes to get any debris out. The check ball in the EUP is very easily damaged. Head is torque in phases. Make sure you lube bolt threads and underside of bolt head lightly. First torque according to chart to 52, then 184. I like to go back over the 184 in sequence til bolts stop creeping. Then turn all bolts 90 degrees in sequence. Then, turn all bolts an additional 90 degrees. Then, tighten M12 bolts to 44 in sequence, the tighten an additional 120 degrees (two flats). I highly recommend new head bolts and clean the bolt threads in the block with tube wire brush and ensure all fluid is out.
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You can reuse the headbolts if a nut spins up the threads fine. I usually replace as it a good practice
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As @pushbroom stated, they now state they can be re-used. This is from my training book from 2011.
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ok now abt injectors.. I saw on a video that said if you change the injectors they will need to be recalibrated with the computer or truck wont run.. a mechanic I talked to yesterday asked me if I pulled the injectors.. I said I will leave them in because I don't have access to a computer .. he has one but don't have the davies 4, he told me that as long as I don't change the injectors, if I am using the same injectors I took out then the calibration wont need to be done.. is this true? I would really like to remove the injectors before pulling the head off. I don't want to damage any.
my next question is about the torqueing sequence again. maybe im a little thick in the head lol but im confused abt something.
by the way I did remove the bolts in the same pattern as the diagrams show.. in reverse order of installation .. started with the m12.I loosened em up a little went on to the m18's, loosened em up a little, then repeated a couple times lossening them up a little more each time. hope I did it right.
ok installing the bolts after replacing gasket.. so in the installation diagram, bolt #1 is in the middle of the block between cylinders 3&4. those are the M18 bolts. phases 1,2,3. all say M18 bolts.so for phases 1-3 im only working with the M18 bolts? skipping the M12's, then on phase 4 im tightening the M18's their final 90 degree and then starting on the M12,s 44 ft-lb,s, then phase 5 is only the m12,s the extra 120 degree turn?.. also you mentioned 120 degrees is two flats.. is that two flat sides of the bolt head?.. so sorry for my numbscullery ..
by the way. I was planning on replacing all the head bolts. I always thought that was a crucial thing due to bolt stretching? a set of new head bolts is about 5 or 6 hundred bucks.. from reading the posts here from you and the other guys I have learned that I can re use the same bolts.. I also went back and re read in the PDF where it also said that.. missed it before.. so super thanks for that..Dave_in_AZ Thanks this. -
I would replace the head bolts, think of it as insurance. You will see how tight those bolts get pulled. Yep, you have the understanding on the head bolt torque procedure. Starts with M18, then M12. Start all just hand tight, then follow procedure. I just put the sequence number on the bolt with a paint marker.
Just flush EUP's with line disconnected, and I highly recommend replacing the pipes from pump to injector. The check ball is a non-return ball, you can take a blow gun and see if it hold pressure after flushing. Just put injectors back in same hole, no need to put calibration code back in.
A bolt is 360 degrees around and a hexagon. Every edge of flat is 60 apart, so 2 "flats" is 120 degree. Might be worth buying a 3/4 torque angle gauge. I have sockets that are marked and torque angle torque wrench.splittero1, SAR, Dave_in_AZ and 3 others Thank this. -
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