[welderwrecker]

Doing head gaskets on my LB7. Sorry I don’t have my truck info filled out…new here and am kinda in a pinch. I’m simply curious if it’s typical to get the heads pressure checked with the injector cups in or out? What have y’all done? Machine shop told me I needed to have the cups installed in order to pressure check the head but I don’t want to put my new cups in a dirty head, especially if there’s a chance it’ll be warped or cracked. Any ideas? Also…will the injector cups need to be trimmed at all depending on how much is taken off the cylinder head or is that not an issue since it projects into the hollow in the piston anyway?

 

[dougmac]

They need to be in with the injectors in place to pressure test the head.

 

[West]

I had my heads tested with the OLD injector cups installed, 2 had to be reinserted because they came out with the injector. The Machine Shop owner told me this was not an issue, he said under pressure they watch for leaks or bubbles of air escaping. When they see a little air esacping around the injector cup they don't worry because they know the source. Once I had the heads home I cleaned the cup seats in the heads very well and installed new cups with Red High Heat Loctite as instructed. Used a good engine assembly lube on the O'Rings so they did not roll on install and put them in place, torqued the injectors to 37 ft lbs in the LB7 and let is sit overnight, 24 hours to cure. Working perfectly since install with no more coolant leaks.
Mark

 

[DMAXfirefighter]

They can't pressure check them without the cups. However, the injectors do not have to be in them to check. The cups do not have to be cut with the heads. Clean the cups and heads up a little where they taper-fit together and send them to the machine shop. When you get them back and reassemble, install your new cups and move forward