Should I use rtv on the water pump?
 

The gasket of the water pump side that mates with the block on my s4 is leaking. I have rtv that I could use, but I have never used rtv before, and the only place I have ever seen it used is on oil pans. I found a guide online that said that it shouldn't be used as a headgasket which is obvious, but I didn't find any information as to whether it should be used on a water pump specifically. Should I use rtv, or should I buy a gasket online? also, which gasket should I use if i buy one online? Will this one from Atkins fit?

https://www.atkinsrotary.com/store/8...86-15-162.html

Thanks for any input.

Just check the leak isnt coming from the little tell-tale hole on the underside of the pump. If so you are due for a new pump.
Yes you can use rtv in a pinch if you do a nice job can be pretty bulletproof but get the gasket.
You local auto parts store should have them.

I seem to remember a thread on this not too long ago, seems to be a polarized question. Some like to use just the gasket, some just RTV, some a combination of the two.

If you have a clean mating surface and plan to torque to spec, I would personally just use the gasket and save the RTV mess for something else.

Yes ive used both methods. Rtv alone can be good but only if it is a quality product and are fastidious. Ie; clean and scrape surfaces like you say (which you have to do anyway) apply minimal rtv very neatly to both to both sides so its even and not getting to much excess squishing inside the pump housing, let tack off for just the right amount of time before snugging it off, then waiting for fuggen 24 hours or whatever before torquing it down.
Its actually a lot of naffing around.
Better off using a gasket, yeah smear that with a tiny bit of whatever, torque to spec and job done.

I like to put a smear on each side of the paper gasket.

me too. please use the newer black or grey sealant, the blue and orange stuff is for Fred Flintstones car

I used some on the pump to housing gasket as the gasket got bent during shipping and I didn't trust it completely. If you can get the gaskets at a reasonable price I don't see a reason to use RTV instead. If you decide to go with RTV use something decent with appropriate material and temperature ratings (not everything tolerates antifreeze, but I guess most general ones will) and smear a thin layer on both sides.


There are two gaskets, I'm not sure where you have your leak. N386-15-162 is the pump-housing to block gasket, N3Y3-15-116 is the water pump to pump-housing gasket. And as mentioned previously, double check that its not the weep-hole as that'd indicate internal pump failure and require a new pump (and at least the pump gasket but probably both).

If you use RTV and no gasket on the S4 aluminum waterpump housing to the engine front iron do not use the two washers that are normally used to make up the thickness of the gasket on the two studs that do not normally go through the gasket.

If you are just using RTV between the cast iron waterpump and the aluminum waterpump housing, no special precautions are necessary.

I have used quality gray RTV (Hondabond, RightStuff Imports, etc) on both locations on my S4 TII with no issues.

I use the Mazda gasket, and a very thin film of Hylomar on both sides of the gasket. Never had a leak doing it this way.

I use the Mazda gasket and like most gaskets, a very thin smear of grease on both sides.
The gasket does the sealing, the grease keeps it from sticking to the mating surface, so no scraping required in the future.

When I did mine 3 years ago or so, I tore the gasket by accident (not the water pump one, but the inner one between the housing and block).

I cleaned everything and reinstalled the torn gasket with a skim of blue RTV, no leaks thus far. Same treatment for the water pump gasket. I'd say if possible, use the gasket + a skim coat of RTV.