1998 7.4 Vortec EGR tube replacement/repair

[MarkC73]

Final update.
Big thank you to TagAllen for the egr tube he had left over from one of his projects. The tube is an exact replacement and will be installed once I get a moment to do so.

 

[TagAllen]

You are welcome.

 

[Crazydavez28]

Stainless commercial gas line for a water heater or furnace is similar yes. It can be purchased in the yellow coated (which will burn off due to that line not being “heat” rated like the stainless EGR tubing).
Also, the JIC flare fittings are far smaller that the fittings on the Vortec 7.4 system.
Only way to change to that style of tubing is to change the inlet/outlet fittings. The one in the intake is easily removed; the one in the manifold however is a different story; not as easily done.
This option is one that’s still on the table of course, but I did finally find one ( I hope it’s right) from a wrecking yard in California. Will update everyone once it arrives if it is correct or not.
As of now, I am just being patient and have my fingers crossed.

Like someone said take the fittings out of each end Intake and Exhaust manifold. figure out the pipe thread sizes and then order stainless hydraulic fittings to adapt to a JIC size you can obtain. Then update this thread with the results. If I get a chance I'll measure the female pipe threads and update.

What is the stock pipe length?

Ok had time to mess with it. Fittings in the manifolds are both the same 6400-14-12 7/8"JIC to 3/4"ORB
Tube is 7/8"ID and 20" Long

Alternatives might be a 1"x18" SS Supply hose and 3/4" ORB to 1 1/4" MNPT Adapters in each manifold.

 

[Schurkey]

Ok had time to mess with it. Fittings in the manifolds are both the same 6400-14-12 7/8"JIC to 3/4"ORB

ORB? Surprised that an O-ring can seal against exhaust manifold heat.

 

[Crazydavez28]

ORB? Surprised that an O-ring can seal against exhaust manifold heat.

it won't but you can switch it out for a copper washer

 

[MICHAEL mgm]

If someone has a egr hose tube i would be gladly to buy it ...

 

[MICHAEL mgm]

PM me. I have one I am not using. Its disconnected from the exhaust but still hooked to the intake. Intake is sitting in my garage.

You still have the egr hose

 

[TagAllen]

no i do not

 

[Bill C]

Ok had time to mess with it. Fittings in the manifolds are both the same 6400-14-12 7/8"JIC to 3/4"ORB
Tube is 7/8"ID and 20" Long

Alternatives might be a 1"x18" SS Supply hose and 3/4" ORB to 1 1/4" MNPT Adapters in each manifold.

curious, did you consider just using 3/4" hydraulic hard line, bend and cut to length, flare to 37* with the right nut and fittings. might cost 100 at local hydraulic supply store. but the stuff is rated at 3500 psi. and 450-500 degrees is nothing for it. bet if you got stainless dom line it would last just fine. the prices people want for these lines used off ebay is insane. 350-450 for a 20 year old line.