Engine Water pump leak driving me crazy

sigsterrr

Active Member

Jan 12, 2019

120

75

38

Florida

Nov 17, 2019

#1

• Nov 17, 2019

• #1

I replaced the water pump when I rebuilt the car (89 GT 5.0) and then had a cooling issue. Replaced the new pump with a high flow pump and can’t seem to get the thing to stop leaking. I’m close to setting my car on fire. I do not have the original. I noticed there are at least two gaskets between the pump and timing cover that fit, but the ports are different. Best place to get the right pump and gaskets? Could the timing cover have been replaced from a different model before I got the car? I’ve tried the black permatex, just gaskets, and only the first time I installed it (with too much permatex) when the engine was on the stand did it not leak. Picture of the proper backing plate? Gasket pictures?

 

2000xp8

SN Certified Technician

Aug 8, 2003

8,024

1,616

194

NJ

Nov 18, 2019

#2

• Nov 18, 2019

• #2

Mustang Replacement Water Pump (79-93) 5.0L PW291 - LMR

Keep your engine cool with an OE style replacement Motorcraft PW291 water pump for your 1979-1993 Mustang 5.0L. Available at LMR.com!

lmr.com

Factory ford pumps are the most reliable.
Comes with the gasket.
High flow is pointless on other than applications that truly need more flow, which in most cases probably require a massive radiator.

 

Blown88GT

Founding Member

Nov 13, 1999

2,283

524

164

Palm Beach Gardens, FL

Nov 19, 2019

#3

• Nov 19, 2019

• #3

I didn't use the gasket that came with the pump. Get the Fel-Pro blue gasket. Then use Permatex gasket adhesive to hold the gasket in place; use no sealant. The mating surfaces must be completely cleaned of all old material; the OEM gasket bonds to the timing chain cover.

 

Reactions: Gs1987GT

Redfire Fox

Active Member

Dec 29, 2011

56

26

39

Dec 8, 2019

#4

• Dec 8, 2019

• #4

Where exactly is your leak coming from? I had a leak that was driving me crazy and took the pump off and on 4 times before I succeeded. Mine was leaking between the water pump and backing plate. There are two bottom bolts holding the backing plate to the pump. My leak was coming from between those two backing plate bolts.

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,249

17,934

224

Massachusetts

Dec 8, 2019

#5

• Dec 8, 2019

• #5

Which water pump are you running?

The only two hig flow pumps I know of are the flowkooler, and the edelbrock.

There were some recent posts on another forum about the FK pump having backing plate bolts thAt the heads were too big and caused the pump to not sit flush to the timing cover

 

2Blue2

will be trying this sex one when I can find it

Mod Dude

Mar 5, 2019

4,430

2,893

163

Oahu

Dec 8, 2019

#6

• Dec 8, 2019

• #6

I have an Edelbrock HF pump on my 65, never had a problem in yeas of yuse
Recently put a Flowcooler on the 77 and it works great and was definitely runs a few degrees lower on the stock temp gauge.
Got to watch that stock back plate on install though.

 

nickyb

I gotta say i never painted my nuts, Never Ever

15 Year Member

Apr 3, 2009

2,979

1,626

153

nevada

Dec 8, 2019

#7

• Dec 8, 2019

• #7

Ditto on back plate! I grinded down an open end wrench to slip in between ,so I could tighten up once installed.works like a charm.

 

Reactions: 2Blue2

Shakerhood

20+ Year Stangneter

Oct 28, 2004

3,356

208

114

Ohio

Dec 12, 2019

#8

• Dec 12, 2019

• #8

2Blue2 said:

I have an Edelbrock HF pump on my 65, never had a problem in yeas of yuse
Recently put a Flowcooler on the 77 and it works great and was definitely runs a few degrees lower on the stock temp gauge.
Got to watch that stock back plate on install though.

Click to expand...

I put an Edelbrock on my Mustang about 20 years ago, still works great.

 

Reactions: 2Blue2