Possible water pump leak - thoughts, please.
10-23-15, 04:34 PM
#1
Pole Position
Thread Starter
Possible water pump leak - thoughts, please.
So about this time last year I did my timing belt, water pump, etc. I used Mitsuboshi belts and an Aisin water pump. Everything went swimmingly & was torqued to spec. Went through a horrifyingly cold winter, no problems.
About a week ago we had our first cold snap and the temps went down into the upper 20's. Yesterday I was going to do my pre-winter maintenance (oil, what-not) when I noticed my water level was down. I looked around under the axle a noticed it was wet around the belts towards the power steering pump and just a tiny bit at the TB cover seal, just by the tensioner.
My first thought: the cold shrunk the metal enough that it broke the seal and water is now leaking through. the water pump came with a metal gasket with (I think) a small rubber seal around the edge, but it may have only been a plain metal seal.
Question 1: has anyone experienced a failure of an Aisin water pump this early?
Question 2: if this is a seal failure, can someone recommend a replacement brand and a sealant to help prevent this in the future?
Thanks.
About a week ago we had our first cold snap and the temps went down into the upper 20's. Yesterday I was going to do my pre-winter maintenance (oil, what-not) when I noticed my water level was down. I looked around under the axle a noticed it was wet around the belts towards the power steering pump and just a tiny bit at the TB cover seal, just by the tensioner.
My first thought: the cold shrunk the metal enough that it broke the seal and water is now leaking through. the water pump came with a metal gasket with (I think) a small rubber seal around the edge, but it may have only been a plain metal seal.
Question 1: has anyone experienced a failure of an Aisin water pump this early?
Question 2: if this is a seal failure, can someone recommend a replacement brand and a sealant to help prevent this in the future?
Thanks.
10-24-15, 10:46 AM
#3
Moderator
hmmm!
OP is getting ahead and projecting based on the surface evidence.
I am listing all this as probable causes, so please do not take offense if you did it DIY or respect the mechanic. But things do happen. And even the things I think are improbable have a chance of happening.
Pump leaks/failure are due to failure to create pressure (circulation) or leak at the bearing. Gasket failure after replacement would be due to bad seal or procedure (mechanic). That does not mean that you can never have cracks in the molding or facing of the water pump was not even (but they are generally very unlikely).
Among the reasons of a gasket failure would be .. re-use of an old gasket, lack of proper cleaning of the engine side, failing to put rtv where and as recommended by the FSM (field service manual ... which includes type and curing time and setting time ,,,, during setting time one is not supposed to move the components, and during curing time you can not add coolant or operate the engine), torque sequence and proper torque ... [with gaskets if you overtorque they are ruined].
With due respect, I disagree with the temp and expansion theory [not that I am saying physics is wrong, but the difference in expansion rate causing seal failure ... all that is built in the design.].
Getting off the soap box, I would suggest open the left and the right timing cover and inspect the source of the leak. There is a hole at the bottom where the leaking bearing would drip. Let the evidence lead you to the actual source of the problem.
Salim
OP is getting ahead and projecting based on the surface evidence.
I am listing all this as probable causes, so please do not take offense if you did it DIY or respect the mechanic. But things do happen. And even the things I think are improbable have a chance of happening.
Pump leaks/failure are due to failure to create pressure (circulation) or leak at the bearing. Gasket failure after replacement would be due to bad seal or procedure (mechanic). That does not mean that you can never have cracks in the molding or facing of the water pump was not even (but they are generally very unlikely).
Among the reasons of a gasket failure would be .. re-use of an old gasket, lack of proper cleaning of the engine side, failing to put rtv where and as recommended by the FSM (field service manual ... which includes type and curing time and setting time ,,,, during setting time one is not supposed to move the components, and during curing time you can not add coolant or operate the engine), torque sequence and proper torque ... [with gaskets if you overtorque they are ruined].
With due respect, I disagree with the temp and expansion theory [not that I am saying physics is wrong, but the difference in expansion rate causing seal failure ... all that is built in the design.].
Getting off the soap box, I would suggest open the left and the right timing cover and inspect the source of the leak. There is a hole at the bottom where the leaking bearing would drip. Let the evidence lead you to the actual source of the problem.
Salim
10-24-15, 07:17 PM
#4
Pole Position
Thread Starter
hmmm!
OP is getting ahead and projecting based on the surface evidence.
I am listing all this as probable causes, so please do not take offense if you did it DIY or respect the mechanic. But things do happen. And even the things I think are improbable have a chance of happening.
Pump leaks/failure are due to failure to create pressure (circulation) or leak at the bearing. Gasket failure after replacement would be due to bad seal or procedure (mechanic). That does not mean that you can never have cracks in the molding or facing of the water pump was not even (but they are generally very unlikely).
Among the reasons of a gasket failure would be .. re-use of an old gasket, lack of proper cleaning of the engine side, failing to put rtv where and as recommended by the FSM (field service manual ... which includes type and curing time and setting time ,,,, during setting time one is not supposed to move the components, and during curing time you can not add coolant or operate the engine), torque sequence and proper torque ... [with gaskets if you overtorque they are ruined].
With due respect, I disagree with the temp and expansion theory [not that I am saying physics is wrong, but the difference in expansion rate causing seal failure ... all that is built in the design.].
Getting off the soap box, I would suggest open the left and the right timing cover and inspect the source of the leak. There is a hole at the bottom where the leaking bearing would drip. Let the evidence lead you to the actual source of the problem.
Salim
OP is getting ahead and projecting based on the surface evidence.
I am listing all this as probable causes, so please do not take offense if you did it DIY or respect the mechanic. But things do happen. And even the things I think are improbable have a chance of happening.
Pump leaks/failure are due to failure to create pressure (circulation) or leak at the bearing. Gasket failure after replacement would be due to bad seal or procedure (mechanic). That does not mean that you can never have cracks in the molding or facing of the water pump was not even (but they are generally very unlikely).
Among the reasons of a gasket failure would be .. re-use of an old gasket, lack of proper cleaning of the engine side, failing to put rtv where and as recommended by the FSM (field service manual ... which includes type and curing time and setting time ,,,, during setting time one is not supposed to move the components, and during curing time you can not add coolant or operate the engine), torque sequence and proper torque ... [with gaskets if you overtorque they are ruined].
With due respect, I disagree with the temp and expansion theory [not that I am saying physics is wrong, but the difference in expansion rate causing seal failure ... all that is built in the design.].
Getting off the soap box, I would suggest open the left and the right timing cover and inspect the source of the leak. There is a hole at the bottom where the leaking bearing would drip. Let the evidence lead you to the actual source of the problem.
Salim
No offense on any suggestions. I asked because no one is perfect; all possibilities are on the table right now. And thank you to all who replied.
A new gasket was used.
Engine side was cleaned, but maybe something was missed. Any advice on proper cleaning techniques that may have been done incorrectly or missed? If I remember correctly it started with 0000 steel wool as suggested by local mechanic, but it made too much of a mess. Switched to 2000 grit wet sand paper, then wiped with clean rag. Was that a mistake?
RTV was used, placement as directed in the manual I have. Maybe it's incorrect?
Will you please specify type, curing time, and setting time?
Everything was torqued to spec (as per manual at my disposal)
I agree with removing the two TB covers and inspecting before tearing everything apart. Although the RTV issue may be the culprit. I recall there being some confusion as to which was best to use. Curing time was based on directions given by the specific RTV. Setting time may also have been off. Does setting time include not installing the TB (putting pressure on the pulley)?
Thank you!
10-24-15, 10:10 PM
#6
Moderator
Thank you for taking my post in the right spirit.
If there is no loss of fluid then our discussion is academic. There are few places the coolant goes to ... IACV, heat exchanger, the cross over pipe (between the two V-banks).
For cleaning the surface, I gently go over with a blade. I wipe the surface down with rubbing alcohol. For the cement, I use Toyota FIPg (there are two types, so match with the need). From squeezing out of the tube to everything torqued down for toyota Fipg is less than 10minutes. Once torqued down, you can slip the belt on. Cure time is about 24hrs. As you long as you follow the manufacturers directions you should be good.
If the torque sequence is not specified, I do center to out.
Salim
If there is no loss of fluid then our discussion is academic. There are few places the coolant goes to ... IACV, heat exchanger, the cross over pipe (between the two V-banks).
For cleaning the surface, I gently go over with a blade. I wipe the surface down with rubbing alcohol. For the cement, I use Toyota FIPg (there are two types, so match with the need). From squeezing out of the tube to everything torqued down for toyota Fipg is less than 10minutes. Once torqued down, you can slip the belt on. Cure time is about 24hrs. As you long as you follow the manufacturers directions you should be good.
If the torque sequence is not specified, I do center to out.
Salim
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