How to Replace Manifold Bolts with Ease
 

I'll share my research on a systematic way to quickly and efficiently get your manifold bolts replaced on your own

You will need the following (per side):

• Qty (6) GM 11547135 Manifold Bolts
• GM 12617944 Manifold Gasket
• Propane Torch

For Bolts Protruding the Head you will need:

• Snap-On MSK-M8125R ($22)

For Bolts Broken within the Head you will need:

• Snap-On E2 Extractor 64780 ($14)
• Lisle 71400 Drill Template

Perform the following steps:

1) Remove vertical wheel well trim and inner wheel well (aprox 20 to 30min)
2) Remove the spark plug wires. Start with sliding the connector off from the coil end, and then with needle nose pliers come in underneath wheel well and remove from the spark plugs by way of the heat shields (20 min) *Note, this is a good time to replace plugs and wires.
3) Remove the Oil Dipstick Retainer (Right Side) (15 min)
4) Heat the manifold to exhaust nuts from under the truck (3 of them) and remove (30 min)
5) Heat each manifold bolt 2min and them remove one at a time. Go slow to ensure you don't break any more than are already broken (1hr)
6) Remove Manifold and Gasket through the wheel well (10 min)
7) If the broken bolt protrudes outside of the head, thread the Snap-On Extractor, and ensure the colette has been tightened so that you cannot tighten it any longer over the bolt. (20 min)
8) Heat the broken bolt and Extractor for 2 min and slowly back the bolt out of the head (10 min)
7a) If the bolt is broken within the head install the Lisle 71400 and follow the instructions to carefully drill out the old bolt with the 3/16 bit (30 min)
8b) Tap the Snap-On E2 within the broken bolt 1/2 inch, heat for 2 min and remove (20 min)

Reverse in the same order for re-install using the new bolts and manifold gasket. Install new bolts with 15nm (first pass), then nuts with 50nm, and then 2nd pass on bolts at 25nm.

Note, there are many extractors in the market place.The two Snap-On tools that I have suggested here are incredibly stronger than most anything you'd buy at a parts store, and you can buy them individually so they are not that expensive. Do not use the extractor that comes with the Lisle template. It simply is not strong enough, but it is a good template. Also, the E2 extractor was so strong that I actually had to cut the old bolt off using a Dremel. Careful not to damage the extractor when doing so.

Thanks for sharing,

Heat and the correct tools go a long way

Neal

Cool thanks, I need to do mine soon.

I did 2 on my rig (back on each side) last December- drilled them by hand without jig, this I would have bought in a second had I known.
Sure would have taken the stress out of making damn sure I stayed centered...
It is a doable job with the inside fender liners removed,
Drivers rear is the tightest I believe, I cut my drill bits to stay very short on angle drill..

Recently did the heads, lifters, push rods, trunions, timing chain and oil pump on my 2003 H2 that had never had the exhaust manifolds removed. Heated each bolt with a pencil torch, followed by penetrating oil and each one came out just fine. Unscrew half a turn, tighten one quarter turn, unscrew another half turn, and so forth. Now why did GM put loctite on those, but not on the valley cover plate? Six of the bolts on the cover plate or not even finger tight!

I had to do this job on both my 05 and 06. The list of tools provided are really helpful. Here's a tool I used to heat the stubborn and frozen bolts: Kelelm 1500W Magnetic Induction Heater Kit. Its a hand held tool with various heads to fit around the bolts head. Comes with different coil sizes for different applications. And you don't have to worry about causing problems by getting open flames in area's that are sensitive to heat. It uses magnetic induction and no flame, this is an amazing gadget that can heat stuck bolts cherry red in less then 30 seconds.

You can get these in various places, Amazon has them as well. They are much more expensive then a simple propane torch (which I used on the 05) but much more effective and if you do a lot of mechanical work this tool is a godsend. I recently help rebuild an I5 from a H3. I can tell you this tool paid for itself again and made frozen and corroded bolts come right out without stripping or breaking. A must for a gear heads tool box especially if your vehicle is from the snow belt.

The procedure provided is dead on and will guarantee success if you follow it exactly, as I said the propane torch will work just fine as I used it with I did my 06. The induction kit is just icing on the cake for those who do a lot of wrenching!

The Key is take you time make sure you have everything you need, start fresh, and don't drink to many beers in the process, lol

Hi, I'm gearing up for this. Did you stick with OEM cast iron or go install stainless? I picked up my SUT in September and thus far have done everything on it myself. Exhaust shop up the street said he'd do it but after a month they still can't get it into the queue. So here I am. I am a union trained tradesman, carpenter, builder of dams and bridges. Used to have to break bolts out of dam forms by climbing above them, tying off myself and my 3' long wrench, putting the wrench on the bolt head and free-fall jumping onto the handle (while hanging over a white water river). Somehow I think I can handle the exhaust bolts. I've done my share of tap and die and we used to use oxy/acetylene to cut beams etc. Going to check out all the tools here and tool up for this and probably everything else. I have plenty of rusted stuck bolts elsewhere to practice on. Any advice appreciated.

Pull the inside fender covers and you will have a clear shot (except the shallow clearance by firewall). Soak the studs hours with kroil. Patience and it’s very doable for you. The welding a nut on a flush stud would make it effortless vs drilling if by firewall. I’ve done this on 2 of my H2’s. Pull the manifolds - you may be able to grab with vice grips (after soaking with kroil). I used Dorman cast manifolds I believe (Orem replacements). I did go with a higher grade hardware on install. Link to Amazon for the Dorman manifolds. I did coat bolts with never seize. The 3 bolts on the existing manifolds going to exhaust if they break on removal obviously Doesn’t matter as they will be replaced so don’t waste much time with coaxing them out. If they snap - so be it.

https://a.co/d/1H8meZS

bolts - https://a.co/d/geLiJDP

Thanks. I ordered the bolts first so I can get an idea of what kind of jig I might want to make in case I have to do precision drilling. I understand from above that the template and other parts resolve this issue, but I want to get the unknown issue (how far to drill if necessary and how to ensure a drill depth stop) out of the way. I was eyeing the inside fender covers, and I realize that will allow me to access a lot of what I want to detail in the engine bay while I'm at it. I just ordered an induction heat bolt breaker and have some bolts in my bed I will break free first. The flux weld kits are only $100, so going to practice with that also. I make precision parts for marine sport on my 3D resin printer and have made custom tools, so patience and precision are already in play. If I come up with anything unique for this thread I will post it.

Go back with the OEM bolts. Heat, not power, is key in this repair. Also, sometimes it helps to break the bolt loose by slight tightening, then loosening. Take your time. You will get them out with the method above.