So the Dorman 90* is what's actually leaking?

 

Yes the Dorman 90's were weeping, leaking. I took off my stock hoses this morning. I compared and measured the Dorman 90 housing and it seems to measure identical to the Ford OEM connectors. They both are one inch opening across the housing. I removed one of the clips from both the heater core and engine side and they are exactly the same, the OEM ones. The Dorman clips appear the same but do not seem quite as sturdy as the factory ones. I took my OEM hoses and Dorman hoses to O Riley's. Casey at O rileys and I looked close at them and There are 2 O rings inside between a plastic washer. So you have one O ring all the way in the bottom and a plastic separator washer then another O ring. Both the Dorman and the OEM are setup the same way except the Dorman has a black washer between them and the OEM has a white plastic washer between the rubber O rings. The OEM housing also is black on the inside beveled edge and the Dorman looks to have a white plastic edge, but the same maybe a little softer. Here is the MAIN DIFFERENCE: The OEM O rings are a little fatter/Thicker and do not flex near as easy as the Dorman O rings. You can see the difference when you look at them, but probably not in a pic unless you have a really good camera. Casey removed all of the O rings from the Dorman 90's and 2 from the OEM connectors. He tried to match up some like the OEM O rings but they were either to slim or larger. SO we took all the factory O rings out and put inside the Dorman 90's. I put the Dorman 90's and gates hoses back on and am currently checking for leaks. So far no leaks, but that doesnt mean anything yet as time will tell. One thing I was more careful about was getting everything into position with the hose clamps loose to make any adjustments to the 90 positions trying to keep them out of a bind. I know the factory hoses just go straight in which is less stressful to the connections.Here are some pics of both connectors, the OEM ones have no O rings in the pic and the Dorman have the OEM O rings inside. The pic of 2 O rings are the flimsy Dorman O rings that were a little smaller. Well I could only load 1 pic and that should be the OEM with out the O rings inside. I will try to resize and post the other pics. But you all should get the idea. We removed the O rings with what looked like a screwdriver ice pick that was L shaped.

 

Here is the Dorman with the OEM O rings installed inside them. If you look closely you will see in the second pic 2 black O rings seperated by a thin black washer. The washer will slide up and down inside. I guess it compress together when you clip it on.

 

The factory retaining/locking clips are the same on the heater core as well as the front of engine, Pic to verify.

 

Here is a pic of the Dorman O rings We removed. These are thinner, weaker as they flex and feel really soft.

 

Here is a pic of my truck with the hoses back on with the OEM O rings inside the Dorman 90's.

 

I am going to take my OEM Ford heater hoses to a ford parts dealer and see if I can get the O ring size or a replacement kit number that has the O rings in them. If we can get the correct part number and my truck does not leak anymore then we should be good. I will do that this week, go to ford and try to find out. You guys may want to wait before you try this because it took time for the Dormans to start leaking. I will watch and check my truck daily and if it develops a leak there again, looks like good old clamps and elbows to make up.
Sorry this turned into such a PITA. One thing to note, you can get the ford coolant diluted also, about $16.00. I will keep you all posted if truck starts to leak again. I think those Dorman O rings were really the problem, but time will tell. If these leak I am going to use or makeup elbows and hose.

 

That is some wonderful info! If all works well ill be ordering my Dormans soon and replacing all the guts with the Ford internals.

Wayne

 

Thanks for the update and detective work......will await your final finds before putting my built hoses back on!

 

Your welcome speedtwin32. I wished these things would have leaked on me from the get go. I was just trying to eliminate so many clamps. One thing I noticed is that on your install you made the small cut on the back of your cover to allow your connections to be free of the cover which should help relieve stress. I noticed that the mustang cover really forces the hoses to the very back of the engine bay and that the heater core connections are a little further out. That might be why SuperSix over at f150online used elbows and clamps to allow the connections to be direct on.http://www.f150online.com/forums/200...installed.html
I am going to ford either tomorrow or Wednesday to see if I can get the correct O ring size and part number. I will take one of my OEM hoses and one of the Dorman O rings in case they have the OEM rings in stock I can make sure they are thicker than the Dormans and verify they fit.