RB26 N1 Waterpump. Anyone have this issue??

[ghost_22_47]

Anyone else have this issue or am I the lucky one with a weird block???

Notice the origanal Water pump has just a single hole but the N1 has a oblong hole?

Well the hole is so big it doesn't match up to the block and coolant sprayed out. Needs to be welded and then re-drilled. I have 2 N1's and it was on both of them, probably because it's for the RB25 and RB26 I think.

[julio]

I just filled my engine with coolant yesterday with a new N1 installed and it leaked from the same spot. I just removed the pump and added more RTV. I am gonna try again later today.

[ghost_22_47]

I'd be careful about that, because we used a mirror to look to see through the oblong hole to see how bad it was and the hole was in the coolant flow area.

Here is a quick paint pic I threw togeather just to make it a little easier.



Actually if I remember correctly now I think the leak was on the right side not left but you get the idea of how it's leaking.

[julio]

hmmm, I'll have to take a closer look then. Thanks for the heads up. I am curious now too as to whether or not others have come across this problem. I would assume so considering its one of the most basic/easiest upgrades for an RB.

[ghost_22_47]

That's why when I saw this on mine I thought "could it be my block" ha ha but most likly not. That why I started this thread. Thanks for responding and maybe I can get enough people with this issue to alert Nissan.

[S13_RB25]

Actually when you upgrade to N1 pump your supposed to screw the bolt back in or this will happen, coolant will leak out. The hole might be like that, oblong hole, but that 8mm bolt is supposed to go back in there.

[julio]

Actually when you upgrade to N1 pump your supposed to screw the bolt back in or this will happen, coolant will leak out. The hole might be like that, oblong hole, but that 8mm bolt is supposed to go back in there.

We both installed the pumps with the 10mm bolt, but as ghost said, the oblong hole extends enough to the passenger's side of the block so that it does not create a seal with the coolant passage way.

After some researching, I found this to be a common problem. People either have it welded shut/re-drill the hole or use epoxy to fill the hole. Either way, it sucks! I wish I would have known about this before I put the engine back together! I guess Ghost and I will be making trips to our local welders to have the situation alleviated. Dammit, I was hoping to start this beast today.

[ghost_22_47]

Actually when you upgrade to N1 pump your supposed to screw the bolt back in or this will happen, coolant will leak out. The hole might be like that, oblong hole, but that 8mm bolt is supposed to go back in there.

Yeah I know that

The houseing doesn't match up with the block and creates a leak path where there is no metal to metal contact for you to use RTV to make a gasket. Meaning there is just a gap where the N1 WP houseing is smaller and doesn't cover the block.
I know the hole has a bolt I was using it as a comparison to better view the issue, and when it sprayed out the bolt was in there .

[ghost_22_47]

Actually when you upgrade to N1 pump your supposed to screw the bolt back in or this will happen, coolant will leak out. The hole might be like that, oblong hole, but that 8mm bolt is supposed to go back in there.

We both installed the pumps with the 10mm bolt, but as ghost said, the oblong hole extends enough to the passenger's side of the block so that it does not create a seal with the coolant passage way.

After some researching, I found this to be a common problem. People either have it welded shut/re-drill the hole or use epoxy to fill the hole. Either way, it sucks! I wish I would have known about this before I put the engine back together! I guess Ghost and I will be making trips to our local welders to have the situation alleviated. Dammit, I was hoping to start this beast today.

Exactly

Yeah I feel your pain on this one mine should be welded by Tuesday and re-drilled same day. I'll try and get a pic before it's re-mounted. I am hoping that because this thread is up that more people will be alerted to this issue and can have it done before they put it on. I wish I had known this. It would have saved me a real headache.

[HxC_Nismo]

that oblong hole is normal, i replaced my water pump with an oem new pump, and it was the same and i just used the nissan rtv and it never leaked for 3 years. i now have an N1 water pump going on my rebuild now and its the same. here is a pic of it installed on my rb26

[julio]

Yea, after a quick inspection with a flashlight and doing some investigative work with a paperclip, I could not for the life of me see or feel anything but the block mating surface in that oblong hole. I just used a little more RTV in that location along with moving the pump to the right as much as I possibly could and have not had an issue as of yet. I think I just used too little RTV the first time around.