Originally Posted by a109drvr
Read this whole thread, quite an education - thanks!
I've got a few questions about my dodge truck. For sealing differential covers would you recommend 598 RTV? These covers don't use gaskets. The repair manual calls for red Mopar silcone sealant or equivalent.
Can I use 518 on my transmission pan and get rid of the gasket? It perpetually weeps every time I change it whether I use an oem or aftermarket gasket. Clearance shouldn't be an issue without the gasket.
Lastly, is there anything I can use that will stop the corrosion on brake caliper bleed valves? I don't have a problem with them sealing, but I'm in the rust belt and tired of using cans of kroil and hoping I don't snap them off.
For stamped assemblies like a rear diff. cover, the gaps are all over the place. Around the bolt heads you'll have a minimal gap, then when you tighten up the bolts, the cover will bow ever so slightly as you torque the bolts. Don't ever use a red RTV on anything that involves fuel, oils, or ethylene glycol-the RTV will break down and leave a drip/puddle on the carport floor. You want to use an RTV like the aforementioned 598, Instant Gasket, or any other RTV that says somewhere on the tube "Sensor Safe" These types of RTV's fall into the oxime cure family rather than the vinegar smelling rtv's which are acetoxy-cure RTV's.
For what it's worth there are many different colors of RTV's in each of the two main single component RTV retail consumers have acess to.
As far as the Transmission pan, more than likely, it is a stamped part like the differential cover. The same holds true with gaps that are all over the place. For wildly fluxuating mating gaps, this is when we choose a suitable RTV.
Gasket Eliminators like 515, 518, 510, etc are for rigid gasketed assemblies where once two parts are mated and torqued up, the gaps are minimal- normally no larger than 0.005" to 0.010". An example of a rigid assembly on an engine would be where the jug mates to the case, or the jug mates to the head, or where the engine case halfs mate.
Good questions-keep 'em coming.
Here a stump the band question for everyone-
Who knows why its so difficult to bond glass?