Stuck valve cover, 350 sbc, 74 GMC

[74flatbed]

Hello,
I did a quick search of the threads and couldn't find anything. Is there a technique to use to get off stuck valve covers besides a rubber mallet (I am hesitating, but am going to buy one this weekend). I've had the truck for two weeks and it looks like a previous owner used adhesive on both sides of the old gasket. I tried warming her up first, taps with a screw driver handle, wiggling back and forth, and trying to get a razor underneath. None successful yet. I also confirmed all the bolts were out. I'll keep searching the threads, I know it must have already been covered.

Thanks,
Paul

 

[yevgenievich]

Rubber mallet and a big flat head screwdriver. Also prying agains the intake with something large to spread the force

 

[Cuba]

When prying with the screw driver, ONLY pry a the bolt holes... this will help prevent distortion of the valve covers. When bolted back down, the bolts will straighten everything back up again. Can't straighten if anywhere in between.

 

[74flatbed]

I will try, thanks. Any preference on the block being warmed up or not? Other forums have mentioned penetrating oil to loosen it up? The bolts had what looked like RTV on the bottom of them when I took them out so I'm wondering if a previous owner just made their own gasket.

 

[Cuba]

Hot or cold for me... never had any difference. You may want to chase the holes & bolts with dies & taps. This will get all the grime off. It will make the bolts thread easier come assembly.

I doubt the PO only used the gasket maker because there's a huge gap in between. Although like many ppl, he may have used too much.

I don't use penetrating oil here either, in fact I usually try to clean off the area the best I can so that when I'm prepping surfaces for reinstall, it makes it that much easier. I blow out all the debris with compressed air when available.

 

[smoothandlow84]

Use a BFM and a flat wide prybar. If destroyed beyond being able to have a flat mounting surface once removed, another option is to replace the valve covers. Valve covers aren't too expensive. If those valve covers are stuck on that well, they may be useless once removed. Sounds like the p.o. had leak problems with them before and more than likely the covers are bent to begin with. I would replace them along with rubber gaskets and a light film of rtv.

 

[Honky Kong jr]

The bad pert you may have to think of if I fact there was a leak issue is what does the rim look like and is there an underlying crank case pressure issue over compensated with glued on covers.

 

[74flatbed]

Bought and used the BFM, worked miracles. The old cork gasket had adhesive on both sides and disintegrated with disassembly. Replaced with rubber gaskets, studs, pressure spreaders, and new valve covers. Didn't do the light film of RTV but that will be my next step probably. After the first few runs around the block, it looks like the leaks have stopped. The back rim on the drivers side had a couple of imperfections, but they looked and felt like casting errors. That's where I'll start with the RTV if leaks show up again. I read on another thread to re-tighten the bolts after one heat cycle, so that'll be tomorrow after work. I also tightened the fitting on the oil pressure line (another leak). There is one bolt that might have a small leak in the intake manifold, so I might pull that one and rtv it to see if I can get a quick fix. If this all pans out, I'll be moving on to coolant flush, transmission flush, and exhaust manifolds (as funds manifest)! Thanks again!

 

[Old77]