Should I use sealant?

[Panzer909]

I'm in the process of a full blown timing belt/water pump/oil seal job at the moment. I'm not exactly sure if I should use some sort of gasket sealant when I install the new pump. My first instinct is to use some. Does this really matter? If so, is there a product you would recommend before I march over to Pep Boys tonight?

[Techno Duck]

I used stuff called Hylomar HPF. It used to be sold by Permatex but they discontinued it for some reason. Its still sold under other companies but i am not sure if you will be able to find something like that in a generic auto store.

Its cool stuff, never dries or hardens...always remains tacky. Glycol, oil and also fuel safe. Original use was for Rolls Royce jet turbine engines..but has tons of usage for automotive now also. Not sure if you can still find it locally though..you may get lucky and find a old tube still on the shelf (i found two at a Pepboys a few months ago which i bought to 'store' when i needed it).

If you cant find the stuff, i wouldnt hesitate to just install it dry. Just make sure the block side is very clean.

[SolReaver]

Spend the extra time preparing the mating surfaces. Clean with a good solvent to remove all grease. I use a very thin film of blue glue (RTV formagasket) to skim coat the gasket. I like a bit under the bolt head to prevent losening up in the future. Another good sealant is Yamabond, available from yamaha dealerships. It is used to glue together case halves. Very sticky and very good at filling in nicks or irregularities on mating surfaces. (use with care, it ain't coming apart again easily) Probably not needed in your case, but nice to know it is out there. If it is not a real pain, you could replace the hardware or at least wire brush the threads as new bolts hold 30% better. Tighten by hand all the way around once and then torque the bolts to spec for that final professional touch.

[Razorback1980]

I use grease on the block side of the gasket so it doesn't stick to the block and I don't have to scrape the gasket off the block on the next change but it tends to fill in the low places to help it seal. On the front almost anything will work...usually go with RTV formagasket like SolReaver but Hylomar works well also.

[Panzer909]

Thanks guys. I'm off to the auto store tonight. I pulled the water pump earlier this week and noticed that they used sealant on the pump side of the gasket and nothing on the block.