[GreyGhost702]

Looking for help regarding injector seal replacement. I have a set of LT4 injectors I bought used low miles, and a seal replacement kit from rock auto for them. I also bought the seal tool from Amazon. I can't for the life of me get the shaper tool to slide over the seals properly. Not a single one. I know I have the correct tool and the correct seal for these injectors. I have watched virtually every how-to video on the net, some of which are just stupid. Like this guy on the 'vette forum "how to replace injector seals with no special tool" takes his punch tool and stretches the seal and then slide it on to the injector. Then the video ends. Yeah, let us know how that worked out for ya when you go to jam that shit into your heads.

My frustration level with this is at a 10/10 and I've done everything I can think of to get this tool to pass over this seal without mangling it. The seal slide back against the injector as the tool starts to taper in size, and then the seal pops up over the lip of the seat and it's game over. Try again. I can't get the seal to stay put. It just wants to get sheered off the injector. My next train of thought is to try applying a heat gun to the seal a little bit, the idea of making it softer and more pliable is all I can think of. I haven't damaged any seals yet, still working with the original 2.

In the videos I've watched these guys just push the tool over the seal like it's no big deal and they do a set of injectors in a few minutes. I set 1 seal and I've got at least 3 hours into this.

[ctrlz]

Can you link to the video referencing your specific injector?
I found this one which has a few tricks, including using a hose clamp to seat the new seals. This guy's "workbench" looks like mine, only mine usually says "amazon"

[GreyGhost702]

Originally Posted by ctrlz

Can you link to the video referencing your specific injector?
I found this one which has a few tricks, including using a hose clamp to seat the new seals. This guy's "workbench" looks like mine, only mine usually says "amazon"

Saw that one. Tried it. Doesn't work. The seal binds up where the hose overlaps because it isn't flush against the seal surface. As you tighten the clamp it essentially pushes focuses the seal into that gap.

To be honest I'm not sure half of these people doing these hokey methods are even reporting on their end results, such as were they actually able to fit the injector into the head, and were the seals undamaged in the process. I have absolutely no doubt you could jam unformed seals into the heads and they will hold a seal. For how long, and how well, that's up to the car gods. Rarely do people make a 2nd video showing how they screwed up, or reporting what failed. It's kind of like forum posts, half of them dead-end and have no conclusion or resolution to the OP's original issue. Sometimes a fix is found and they just move on with their lives and don't tell the rest of the world what the outcome was lol.

[GreyGhost702]

Furthermore, these "no tool" methods do not form the seal down to the proper tolerances they need to be to fit in the head properly. The seal has to be "smushed" down to the proper thickness and as it's smushed it fills up the seal seat out to the edges. This tool I have, now that I have properly destroyed a set of seals, it really crushes the seal down to damn near the width of the injector tip. If you look at this guys hose method, the seal isn't really smushed down enough. His seals are still much thicker than the injector tip. While his injector may fit in the head far enough to bolt the rail down, I'd like to see pictures of the injector tip protruding at the combustion chamber, and really a test fit of the injectors individually, to see if the seals didn't get mangled by the head as they went in. All you'd need to do is set one in the head and pull it back out. If the seal didn't move or get scratched to death, then fine he's good to go. I'd wager money they are just jammed in there.

Again, we're going back to it may have worked out for him, and he didn't have leaks, but is he sitting on a failure that the clock is just ticking for.

[ctrlz]

Some tips from an audi guy with similar struggles below. I've read different approaches suggesting motor oil, wd40, or silicone spray as lube. Others say absolutely NO lube for this application. I would certainly shy away from petroleum lubes or wd40, as those might swell the seal. A bit of silicone spray might be ok here.
https://www.audizine.com/forum/showt...ector-seal-Q-s

This one makes it look easy. Can you link to the amazon tool you bought?


another one. Says it helps to let them shrink overnight:
https://www.thedrive.com/guides-and-...r-seal-service

[GreyGhost702]

Originally Posted by ctrlz

Some tips from an audi guy with similar struggles below. I've read different approaches suggesting motor oil, wd40, or silicone spray as lube. Others say absolutely NO lube for this application. I would certainly shy away from petroleum lubes or wd40, as those might swell the seal. A bit of silicone spray might be ok here.
https://www.audizine.com/forum/showt...ector-seal-Q-s

This one makes it look easy. Can you link to the amazon tool you bought?


another one. Says it helps to let them shrink overnight:
https://www.thedrive.com/guides-and-...r-seal-service

https://www.amazon.com/gp/product/B088TLZBRT

This is the tool I ordered. While most of the reviews seem to indicate successful use, there's one near the top that says "Don't Buy" and his review is exactly my situation.

I have come to the same conclusion as the guy in the Audi post, and that Amazon reviewer, I think the amazon tool's taper is too aggressive and it's causing the seal to be pushed over the back edge of the injector seat. There's no kind of backing to put against the edge of the seal to keep it on the injector seat, while the tool smushes over it. The tool itself is just pushing the back half of the seal over the seat rim, and then the the tool can't be pushed back anymore or you risk damaging the seal.

I ordered a different tool, the one from Rock Auto seems to be a better tool, it goes for 2x the price anywhere else. I don't mind spending the money if the tool works. I will send the Amazon one back, because Amazon. It was $15 and worth a try, but I can say for a fact it's not the solution for our particular injectors. But definitely the taper needs to be smoother in transition and the amazon tool tries to compress the seal within I would say 5/16" cone depth, and that's severe. If they made that taper more like 5/8" in depth, I think the seal would cooperate.

After this debacle, I am definitely going to keep my LT1 injectors on hand. After this build is off my plate, I am going to attempt to create a better press tool. This business of sliding a tool over the seal to press it is borderline cave-man stuff. I think with a 3D printer and (if the prototype works) a CNC machine, a press tool could made that wraps around the seal, and then mechanically squeezes the seal to its proper thickness. The most simple method I can think, would be like taking the amazon tool and cutting it in half, drill a set of screws into either side, and like a clam shell from both sides, sinch down on the seal surrounding it. Rather than trying to drag a piece of steel over the teflon seal and crossing your fingers that it'll cooperate.

We'll see how this new tool does though, maybe it'll work slick compared to the amazon tool. No need to reinvent the wheel if it does work well. I just think it can be done better. I'd bet that's how it's done at the injector factory, the injector barrel is set in a press vice with the seals in place, and the press vice comes down on it with a barrel cast in the exact shape the seals need to be to be proper thickness. Essentially the seals get stamped. That's how I would create a hand tool, and just use screws to pull the cast together to compress the seals.

[ctrlz]

Yeah, a lot of reviews there saying the taper is too steep and it's pushing the seal out of the groove.
Hopefully success with a better tool.
Another idea I had was heating the tool to maybe 200-250 degrees to get the "O" shape to expand slightly. May buy you a small fraction of room. Don't want to go much hotter than operating temp for the engine. Then cooling may help it compress.
Any way you do it, going slow seems to be key.

[GreyGhost702]

Originally Posted by ctrlz

Yeah, a lot of reviews there saying the taper is too steep and it's pushing the seal out of the groove.
Hopefully success with a better tool.
Another idea I had was heating the tool to maybe 200-250 degrees to get the "O" shape to expand slightly. May buy you a small fraction of room. Don't want to go much hotter than operating temp for the engine. Then cooling may help it compress.
Any way you do it, going slow seems to be key.

Yeah I thought about doing heat there for a minute and decided against it. It's Teflon material. That stuff doesn't really change consistency just because it's hot, but once it gets to its threshold, then it just breaks down and melts. That's likely why they prefer to use that material for the internal seals vs rubber. Rubber will change shape on you, expand, and likely push off the seat. It's also not rigid enough to hold back the extreme pressure of the combustion chamber.

As far as going slow, I think methodical is the key. Once the seal is smushed, leaving it for a minute is just good form, but I don't think necessary. I think the key is, once the seal is pressed, don't jack with seal anymore. If you play with it and make it spin, you're technically unseating it. The Teflon is firm but malleable, for reasons like I talked about above, it has to withstand heat and extreme pressure, but hold a specific shape and thickness. None of the guys in the other videos were taking more than what seemed to be an hour or so to do a set of injectors and then installing them.

[GreyGhost702]

Just to follow up with this thread, the injector seal press tool I ordered from Rock Auto worked like a charm. So much easier. Did a set of 8 injectors in about 30 minutes. The Amazon tool's taper just isn't right, it's super aggressive and doesn't give the seal a chance to seat before it just pushes it over the lip of the seat. The GB Reman tool works great. Pay attention the directions regarding the seal pusher, or you'll end up in trouble with the cone.

[Baddawg53]

Originally Posted by GreyGhost702

Just to follow up with this thread, the injector seal press tool I ordered from Rock Auto worked like a charm. So much easier. Did a set of 8 injectors in about 30 minutes. The Amazon tool's taper just isn't right, it's super aggressive and doesn't give the seal a chance to seat before it just pushes it over the lip of the seat. The GB Reman tool works great. Pay attention the directions regarding the seal pusher, or you'll end up in trouble with the cone.

Can you post a link? I'd like to get one for myself

[ctrlz]

Greyghost, glad it worked out.
I would post a negative review on amazon and mention the tool that works.