The Problem:

My head gasket seems to have sprung an external leak right under my thermostat.  I've got a big trip coming up next month with a pregnant wife, a 4 year old, and a 7k trailer on mountain roads, so I've got to get this squared up, and done correctly (though not overkill).  I'm very capable with a wrench, and have been through every facet of gassers over the last 20 years, so I'm not worried too much about tackling it (other than the 200lb weight of the head).

 

As I move forward I have a couple of planning questions to ask.

 

What tools will I need other than the basics (I've got a decently stocked roll away with the basics)? 

I don't mind spending up to 50 dollars for a job, or engine, specific tool that I'll someday need again that will make the job appreciably easier, but I don't mind making do to save some cash either.  I have a barring tool, but that's the limit of my Cummins specific stuff.  Should I get an injector puller?  Anything else?

 

What gaskets will I need?

I'm planning on buying Genuine Cummins (have a local dealer).  I figure I'll need a full top end set (PN 4090035), are there any additional gaskets or parts that I'll need other than head fasteners (see next question)?  Injector seals?  Anything?

 

Bolts or Studs?

I know studs aren't truly needed unless I'm pushing higher boost numbers than I'm likely to ever hit, but I don't mind springing for it if there is an appreciable level of genuine peace of mind to be had from it.  I hear that bolts can be reused, and often are, but there seems to be a lot of voices saying not to, which is pushing me to at least replace the bolts (approx $120 for a set).  I would really be bummed to shell out for that, when a new set of studs is not a whole lot more ($405 for ARP 425 series).

 

Tips?

I've got an alldata subscription which will give me most of the steps that I need, but I welcome any tips, shortcuts or encouragement you can offer. 

 

Other things of note:

- Currently my oil is not milky, and I can't see any evidence of oil in my coolant, so I think my leak is external only.

 

- I won't start this job until the end of next week.

 

- Once off, I AM planning to get the head surfaced, and checked for cracks... Is there anything else I should have them do?

 

- To do this job carefully, and on the slow side, what should I ballpark for time spent on actual work (not waiting for machining, etc)?

 

- My truck is my daily driver.  I don't ever plan on making it a beast.  At this point I'm happy with it's current power output, and really only could imagine going up to 400 hp on the outside. 

 

- I'm the sort of person who wants to do things the right way, the first time.  I don't go overkill nuts, but I also don't need to skimp to save $20 that I may regret later. 

 

All help is appreciated

Edited June 11, 20159 yr by Nates1999

As far as I know of basic hand tools should be the only thing you'll need. I would be careful with exhaust hardware being most of it will be rusted. As for gasket most suggest Cummins gaskets. Bolts are fine studs you could as a upgrade but adds cost to the project. From the people I've talked to its rather straight forward on doing a head gasket. TFaoro would be excellent man to talk to since he's doing the full tear down.

The Problem:

My head gasket seems to have sprung an external leak right under my thermostat.  I've got a big trip coming up next month with a pregnant wife, a 4 year old, and a 7k trailer on mountain roads, so I've got to get this squared up, and done correctly (though not overkill).  I'm very capable with a wrench, and have been through every facet of gassers over the last 20 years, so I'm not worried too much about tackling it (other than the 200lb weight of the head).

 

As I move forward I have a couple of planning questions to ask.

 

What tools will I need other than the basics (I've got a decently stocked roll away with the basics)? 

I don't mind spending up to 50 dollars for a job, or engine, specific tool that I'll someday need again that will make the job appreciably easier, but I don't mind making do to save some cash either.  I have a barring tool, but that's the limit of my Cummins specific stuff.  Should I get an injector puller?  Anything else?

 

To pull the crossover tubes, remove all of the lines, then you can use a pair of needle nose pliars on the OUTSIDE of the tube and pull them out. Some can be tough if they've never been out.

To pull the injectors just pop one of the bolts out of the valve cover (Just push it out the top and the rubber seal will release) then screw the bolt into the injector and pull up. Once again some can be tough.

Make sure you have a big torque wrench to tighten the studs. I would go with a minimum of 150 ft-lb wrench.

 

 

What gaskets will I need?

I'm planning on buying Genuine Cummins (have a local dealer).  I figure I'll need a full top end set (PN 4090035), are there any additional gaskets or parts that I'll need other than head fasteners (see next question)?  Injector seals?  Anything?

 

Injector sealing washer, injector sealing O rings, crossover tube O rings, grid heater gaskets, tappet cover gasket, intake plenum gasket, head gasket, Banjo washers for back of head, T return line seals. I think that's all I will update if I remember more. Compare what the kit comes with to this list.

 

Bolts or Studs?

I know studs aren't truly needed unless I'm pushing higher boost numbers than I'm likely to ever hit, but I don't mind springing for it if there is an appreciable level of genuine peace of mind to be had from it.  I hear that bolts can be reused, and often are, but there seems to be a lot of voices saying not to, which is pushing me to at least replace the bolts (approx $120 for a set).  I would really be bummed to shell out for that, when a new set of studs is not a whole lot more ($405 for ARP 425 series).

 

You only want to do this once, so you should probably get a set of studs (at least that's my opinion.) Speak with the vendors here on the site and see if they will make you a package deal on everything you need. If you just order online you will pay full price for everything.

 

Tips?

I've got an alldata subscription which will give me most of the steps that I need, but I welcome any tips, shortcuts or encouragement you can offer. 

 

See below.

 

Other things of note:

- Currently my oil is not milky, and I can't see any evidence of oil in my coolant, so I think my leak is external only.

 

- I won't start this job until the end of next week.

 

- Once off, I AM planning to get the head surfaced, and checked for cracks... Is there anything else I should have them do?

 

If you can have them check to see if the valve guides or valve stems are worn. This will induce leaking later on if they are. I would replace valve seals at a minimum depending on miles.

 

- To do this job carefully, and on the slow side, what should I ballpark for time spent on actual work (not waiting for machining, etc)?

 

This depends on your mechanical ability. I had a motor, trans, transfer case and all other related parts to removing the engine out in one day. I also removed the head and valves that same day. For me, I think I could have the head out in under 2 hours.

 

- My truck is my daily driver.  I don't ever plan on making it a beast.  At this point I'm happy with it's current power output, and really only could imagine going up to 400 hp on the outside. 

 

- I'm the sort of person who wants to do things the right way, the first time.  I don't go overkill nuts, but I also don't need to skimp to save $20 that I may regret later. 

 

Good. I am in the same boat and that's why my motor is in a million pieces and the block & head are at a machine shop.

 

All help is appreciated

 

I'll give a short rundown of what needs done here. Some responses are above in bold.

 

#1 Take the insulation off the top of the firewall!!!! This will make the process 10X easier.

Drain all of the coolant (Driver side of the radiator there is a plug. pull and twist and it will come out. Don't take it all the way out or coolant everywhere!)

While the coolant is draining start on the passenger side.

Pull the airbox out (I suppose this is optional but I would for room)

Remove the turbo drain and supply lines (Make sure to plug both holes with tape/rags ect)

Remove the turbo and manifold (if you are strong it can be done in one piece)

Remove the coolant line going to the heater core and plug it

On to the driver side

Remove the intake horn, apps bracket, and grid heater (Throw rags in the intake plenum and charge pipe to keep them clean)

Unhook the IAT sensor MAP sensor, and engine temp wires (Near the back of the head on the first two - front of the head for the last one)

Remove all 6 injection lines (Might have to remove the engine removal bracket at the back of the head to get to 5 & 6)

Remove all 6 crossover tubes (Explained above. Reinstall the bracket at the back of the head when you're done if you removed it.)

Remove all 12 rockers and bridges (Set them to the side separately, in order, and label them so that you put them back in the same spot)

Remove all 12 pushrods (Same thing - keep them in order and know which are exhaust and which are intakes) To remove #5&6 there are two rubber plugs in the top of the firewall. I can't remember if they have to come all the way out the top, or if you can just push them in there then twist out to the side. If the have to come out the top, remove both windshield wipers at the base, and unscrew the 5 plastic holders across the top of the "black piece." That one is pretty easy to remove, if need be.

Remove all 6 injector hold downs and all 12 bolts. Start with the bolt on the passenger side, take it all the way out, remove the hold down, then remove the driver side bolt. (Again separate them)

Use a valve cover bolt to remove the injectors (Sometimes it can take some strength!)

Remove the fuel return banjo at the back of the head

Remove all 26 head bolts

Remove the top radiator hose and plug the radiator

Use a cherry picker to remove the head off the top of the engine (Using the engine removal brackets.) These heads aren't light, and I don't think there is a safe way for one or even two men to remove it carefully without a cherry picker.

That is a very non critical spot and is common spot to leak. How bad it leaks makes the difference in the approach. When I worked at the truck shop and saw this on a monthly basis believe it or not we got about 75% of them to seal up by adding some GM seal tabs and doing a retorque on the head if it was just showing signs of leaking, I have even seen the seal tabs alone seal up the weep in that area. If wanting to pull the head then it is very basic, no need to take the exhaust off from the head just the intake pipe and exh pipe from the rear of the turbo and pull it as a single unit.

I would go right back in with the stock head bolts unless you plan to add power and boosting in the future. If the stockers are rusty and pitted then you can choose new bolts or studs but if they look fine reuse them.

My 02 cummins showed the signs of this leak @ under 50K and I did the approach above and ran it hard for another 100K @ 560 hp power pulling and a few drags and it never showed up again.

That is a very non critical spot and is common spot to leak. How bad it leaks makes the difference in the approach. When I worked at the truck shop and saw this on a monthly basis believe it or not we got about 75% of them to seal up by adding some GM seal tabs and doing a retorque on the head if it was just showing signs of leaking, I have even seen the seal tabs alone seal up the weep in that area. If wanting to pull the head then it is very basic, no need to take the exhaust off from the head just the intake pipe and exh pipe from the rear of the turbo and pull it as a single unit.

I would go right back in with the stock head bolts unless you plan to add power and boosting in the future. If the stockers are rusty and pitted then you can choose new bolts or studs but if they look fine reuse them.

My 02 cummins showed the signs of this leak @ under 50K and I did the approach above and ran it hard for another 100K @ 560 hp power pulling and a few drags and it never showed up again.

I was told these are torque to yeild which means they should never be reused. I wouldn't either way though.

You were told wrong, with your head gasket kit "if it is OEM Cummins" there will be a head bolt reuse tool which consists of a plastic cut out measuring device you lay the bolt against to measure the length and it shows a good and bad reuse range on it. I have never seen a head bolt stretched out of range using their tool but have replaced most from being rusty and pitted.

You were told wrong, with your head gasket kit "if it is OEM Cummins" there will be a head bolt reuse tool which consists of a plastic cut out measuring device you lay the bolt against to measure the length and it shows a good and bad reuse range on it. I have never seen a head bolt stretched out of range using their tool but have replaced most from being rusty and pitted.

Thank you for the clarification!

So in the end you agree studs would be a better option? I don't think it's a bad idea to go a bit overkill when it comes to holding the head down.

Studs will always be a better clamping fastener than bolts but it all depends on needs and funds one wants to go with. If at or under 500 hp and 40psi and never going over I would stick to bolts.

As W&F noted they are not TTY bolts, but there is a length guide for them that needs to be checked prior to reinstallation. 

 

Studs are always better than bolts but may not be needed. Be sure to lube the crap out of the bolt so the torque is on the threads and not the bolt/head surface. 

One other question. How likely am I to need a valve job with 150k on the clock?

50/50... have them do a vacuum check. 

So 200k would be more like 60/40?

My dad's 06 head just came out of the shop and it was 100% good at 123K. When my head was inspected at 93K I ended up with 2 new exhaust valves but they where not bad, but thinner than the shop wanted once they where reground.

Man the local prices for a valve job, and general head rebuild are killing me...  Been quoted 500-750 dollars.  This is going to be one darn expensive gasket.  Interestingly, in talking with a lot of the local guys (including my local cummins shop) they generally recommend reusing the stock bolts if they are not bad (as has been mentioned here).

Edited June 11, 20159 yr by Nates1999

Here's a couple of pics of the leak

I would seriously add some GM seal tabs and just do a re-torque for starters, that is not a bad leak yet. If it keeps leaking after the trial then jump to a new gasket. Ten bucks or so for the tabs and about an hour for the retorque is still a better bet to start with than jumping into a head job. Like I said prior my 02 did this at around 50K miles and I did the tabs and retorque and it never leaked again.

Those seal tabs are awesome, I have even seen GM Good wrench reman engines with them in from the rebuild facility. At the truck shop we actually put them in any time we did any engine work or coolant system work.

Man the local prices for a valve job, and general head rebuild are killing me...  Been quoted 500-750 dollars.  This is going to be one darn expensive gasket.  Interestingly, in talking with a lot of the local guys (including my local cummins shop) they generally recommend reusing the stock bolts if they are not bad (as has been mentioned here).

My head is costing 1,280+ and yes that's a comma in there.  Stock head with 188k on it.

My head is costing 1,280+ and yes that's a comma in there. Stock head with 188k on it.

Yikes!! I guess after gaskets and studs I could be there too if I go that direction.

You were told wrong, with your head gasket kit "if it is OEM Cummins" there will be a head bolt reuse tool which consists of a plastic cut out measuring device you lay the bolt against to measure the length and it shows a good and bad reuse range on it. I have never seen a head bolt stretched out of range using their tool but have replaced most from being rusty and pitted.

 wow, when i rebuild my tractors eng. [john deere]     i also reused the head bolts & thats where the 'fun' began,  i had some stretch [wouldnt torque to ft. #] but the 1st one that did this just wouldnt get tite so i just kept turning.  .......& then SNAP!!         NOW WHAT!!!!               thank fully i was able to just back it out w/ a sharp chisel........whewww! 

 

point of lesson, dont just use them....check them 1st!  and if they dont get tight, stop!    

Edited June 12, 20159 yr by organicfarmer

Yikes!! I guess after gaskets and studs I could be there too if I go that direction.

That's just machining on the head though. I've got everything else to buy still.

You have to remember the coolant pressure on the head gasket is about 40 PSI. I've found it about a year ago where a member on CF hooked up a pressure gauge and showed the pressures at the head. It varied of course but the max pressure I remember seeing is 35-40 PSI. This is pressure created by the water pump.