gasket sealer or no gasket sealer?

91convguy · 03-27-2009, 01:43 AM

I am about to install a new water pump and a new water pump housing gasket not sure what to do here long time friend and X-mechanic tells me I'd be defeating the purpose of the gasket buy using gasket sealer,makes a little bit since to me. But the Hanes manual tells you to put a thin coat on gasket just between engine and gasket (just one side of the gasket) and sum between water pump and gasket. Someone else told me to put a thin coat on both sides both gaskets put it together and wait a day then add coolant. I myself think it would be best if it was applied on the gasket side that's going up against the housing on both gaskets an that's it.

TheDriver216 · 03-27-2009, 03:13 AM

i always have applied a thin coat of blue rtv sealant on both sides of the gaskets.. housing to block and water pump to housing.. also it makes it easier for me to install since it sticks in place so the holes always line up

djmtsu · 03-27-2009, 06:57 AM

I concur!

killahrx7 · 03-27-2009, 07:26 AM

i also use a thin coat of silicone for some insurance.

***TitaniumTT*** · 03-27-2009, 07:37 AM

Yup, I've always used RTV on both sides of the gaskets. Blue or black for coolant. I used black this time around because the iron, housing, and pump were..... well - black.

A little bit goes along way though, and whatever squeezes out that you can see, its a good bet that the same amount has squeezed out on the inside too. So, if it's too much, don't hesitate to pull it apart and clean a little up an re-apply.

classicauto · 03-27-2009, 03:32 PM

Plus, it'll make it easier to remove the gasket if you've ever got to tear down the engine.....some of the cheap ass aftermarket paper gaskets I've found on various engines that are put on dry have to be chiseled/scraped and cursed at before they come clean.

***TitaniumTT*** · 03-27-2009, 06:13 PM

cursed at

I prefer to fix those with fire

91convguy · 03-27-2009, 10:46 PM

Well looks like I need to go out and get some sealer. The car has 149,000 I bought the car with 46,000 miles, about sure this is the factory pump I think the pump is still good but going to change it anyhow. The gasket behind housing was leaking, well in response to last posts it took couple hours of careful scraping. I found that break cleaner was a real help getting old gasket off. Getting it ready for the Dragon!! PEACE.

***TitaniumTT*** · 03-28-2009, 12:49 AM

Roloc pads are awesome too.

One tip - put the gaskets in place without sealer, snub it up... not torqued to spec but tight and make sure the waterpump spins freely. I've had, on more than one occasion, a waterpump whoes impeller was not in the proper place and bound against the housing. You can imagine the noise and belt chewage that insued preceding the foul words that were emmited.

Whizbang · 03-28-2009, 12:51 AM

i generally use no paper gasket and use RightStuff

rx4ur7 · 03-28-2009, 03:28 AM

As was told to me at GM, Porsche and Mazda schools in a perfect world where everything could be machined to tolerance there would be no need for gaskets. In the world of mass production these tolerances really can not be maintained therefor the need for gaskets. Still in all schools sealant is not recommended when using a gasket. Except in very specific applications. If you have cleaned surfaces properly the gasket will work by itself. If a sealing surface has been cleaned by rough scrapping or grinding the old gasket off with power sander, then one may have to use something. In the 40 years of working on motor vehicles I rarely resort to the use of RTV or sealent unless recommended by manufacturer. Mazda does recommend the use of HYLOMAR in a few places. But not water pumps. If you have to use anything use very sparingly. Don't know how may rotaries I have had to replace that have had RTV blocking the cooling passages in rotor housings causing overheat and premature engine failure from overheating.

TitaniumTT does make a good point, I have also come across a few pumps from Mazda in the recent past (FD3S's) that have had clearence issues, never saw one before that. Very uncharacteristic for Mazda in all the years I have worked on them. It was when they changed supplier. I put it to influences outside of Hiroshima that have made them use cheaper parts.

classicauto · 03-28-2009, 11:28 AM

Throwing out a random tip here:

When you're scraping a gasket off of anything aluminum, use a plastic scraper. There's all kind of them available, and can be resharpened as needed. No better way to make something leak then to create a big gouge in it with some wood chisel while cleaning off an old gasket.

rx4ur7 · 03-29-2009, 10:43 AM

Excellent tip classicauto. Also there are some good gasket removing chemicals, really nasty stuff but they do make for a clean surface without any heavy scrapping. You just have to be patient.

03-27-2009, 01:43 AM	#1
91convguy The Newbie Join Date: Feb 2009 Location: Central Ohio iTrader: (0) Posts: 12 Rep Power: 0	gasket sealer or no gasket sealer? I am about to install a new water pump and a new water pump housing gasket not sure what to do here long time friend and X-mechanic tells me I'd be defeating the purpose of the gasket buy using gasket sealer,makes a little bit since to me. But the Hanes manual tells you to put a thin coat on gasket just between engine and gasket (just one side of the gasket) and sum between water pump and gasket. Someone else told me to put a thin coat on both sides both gaskets put it together and wait a day then add coolant. I myself think it would be best if it was applied on the gasket side that's going up against the housing on both gaskets an that's it. Last edited by 91convguy; 03-27-2009 at 01:52 AM.. Reason: missed some words

03-27-2009, 06:57 AM	#3
djmtsu My minds tellin' me no... Join Date: Feb 2008 Location: Murfreesboro, TN iTrader: (10) Posts: 4,043 Rep Power: 21	I concur! __________________ 1976 Mazda Cosmo RX-5 1976 Mazda Cosmo RX-5 2003 Toyota Tundra TRD 2015 Toyota 4Runner SR5

03-27-2009, 07:26 AM	#4
killahrx7 Rotary Fan in Training Join Date: Mar 2009 Location: covington ga iTrader: (0) Posts: 31 Rep Power: 0	i also use a thin coat of silicone for some insurance. __________________ 88 turbo II(streetsweepah) 13b rew full bridge wolf3d v500 tuned by 3FACE RACING. bigup Waynespeed and Juankel Performance

03-27-2009, 10:46 PM	#8
91convguy The Newbie Join Date: Feb 2009 Location: Central Ohio iTrader: (0) Posts: 12 Rep Power: 0	Thank's for the info fellow rotor heads. Well looks like I need to go out and get some sealer. The car has 149,000 I bought the car with 46,000 miles, about sure this is the factory pump I think the pump is still good but going to change it anyhow. The gasket behind housing was leaking, well in response to last posts it took couple hours of careful scraping. I found that break cleaner was a real help getting old gasket off. Getting it ready for the Dragon!! PEACE.

03-28-2009, 12:51 AM	#10
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	i generally use no paper gasket and use RightStuff __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

03-27-2009, 03:13 AM	#2
TheDriver216 Rotary Fanatic Join Date: Feb 2008 Location: Cleveland, Ohio iTrader: (1) Posts: 159 Rep Power: 17	i always have applied a thin coat of blue rtv sealant on both sides of the gaskets.. housing to block and water pump to housing.. also it makes it easier for me to install since it sticks in place so the holes always line up

03-27-2009, 07:37 AM	#5
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	Yup, I've always used RTV on both sides of the gaskets. Blue or black for coolant. I used black this time around because the iron, housing, and pump were..... well - black. A little bit goes along way though, and whatever squeezes out that you can see, its a good bet that the same amount has squeezed out on the inside too. So, if it's too much, don't hesitate to pull it apart and clean a little up an re-apply.

03-27-2009, 06:13 PM	#7
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	cursed at I prefer to fix those with fire

03-28-2009, 12:49 AM	#9
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	Roloc pads are awesome too. One tip - put the gaskets in place without sealer, snub it up... not torqued to spec but tight and make sure the waterpump spins freely. I've had, on more than one occasion, a waterpump whoes impeller was not in the proper place and bound against the housing. You can imagine the noise and belt chewage that insued preceding the foul words that were emmited.

03-28-2009, 03:28 AM	#11
rx4ur7 Rotary since 1972 Join Date: Nov 2008 Location: Tucson iTrader: (0) Posts: 231 Rep Power: 16	As was told to me at GM, Porsche and Mazda schools in a perfect world where everything could be machined to tolerance there would be no need for gaskets. In the world of mass production these tolerances really can not be maintained therefor the need for gaskets. Still in all schools sealant is not recommended when using a gasket. Except in very specific applications. If you have cleaned surfaces properly the gasket will work by itself. If a sealing surface has been cleaned by rough scrapping or grinding the old gasket off with power sander, then one may have to use something. In the 40 years of working on motor vehicles I rarely resort to the use of RTV or sealent unless recommended by manufacturer. Mazda does recommend the use of HYLOMAR in a few places. But not water pumps. If you have to use anything use very sparingly. Don't know how may rotaries I have had to replace that have had RTV blocking the cooling passages in rotor housings causing overheat and premature engine failure from overheating. TitaniumTT does make a good point, I have also come across a few pumps from Mazda in the recent past (FD3S's) that have had clearence issues, never saw one before that. Very uncharacteristic for Mazda in all the years I have worked on them. It was when they changed supplier. I put it to influences outside of Hiroshima that have made them use cheaper parts. Last edited by rx4ur7; 03-29-2009 at 10:40 AM..

03-29-2009, 10:43 AM	#13
rx4ur7 Rotary since 1972 Join Date: Nov 2008 Location: Tucson iTrader: (0) Posts: 231 Rep Power: 16	Excellent tip classicauto. Also there are some good gasket removing chemicals, really nasty stuff but they do make for a clean surface without any heavy scrapping. You just have to be patient.