need part # for a radiator cap

[Rick Kirchner]

Looks like I may have replaced my radiator cap with the wrong type. It's not sealing and water is just blowing into the catch can.

Looking for the Stant part number for the cap that fits a Van Diemen neck.

[Daryl DeArman]

Rick,

It appears there are only 3 diameter caps made by Stant: 31mm ID, 32mm ID, and 2.125" OD. There also appears to be 3 different depths. The "metric" caps look like 10mm or 16mm depth. The SAE size looks like all are 3/4" deep.

They have a decent website with part numbers based on these two measurements, pressure rating and style.

Good luck. May not be much help, as someone else probably knows the exact part number, but you may find you have a 31mm cap on a 32mm neck or a faulty cap.

[Rick Kirchner]

After further review, it looks like it might be a sealing problem caused by a dent in the sealing bead.

Funny thing - the old cap never leaked, two new ones do, so, either I have the wrong size and it's subtle, or the gasket material on the old cap was softer and sealed the dent.

Figured this out after going to the Stant site and making some measurements, then took a look down the neck, polished it up, put a little blue on the gasket and the dent stood right out.