Rb25/30 Water Pumps... Need Advice!

[czar02]

hi guys!

my water pump is leaking coolant in the #1 hole of the water pump which is where the M6 bolt goes in.. 100k service was done at start of this year and only noticed it last month that there was no bolt on the M6 hole..

my question is, what is the difference between the rb25 and rb30 water pump? i've also looked through pictures online and they seem to be similar and the rb30 can be fitted on an rb25de engine..

i went to the mechanic today and showed him that there was a bolt missing on the water pump.. he told me that he fitted a 'high performance' rb30 water pump and it was bigger than the OEM water pump.. he didnt include the M6 bolt because the holes don't line up.. he also showed me some of the works he's done in his workshop with the M6 bolt not fitted..

the M6 hole on my water pump is not an elongated one found on the rb30's.. and got me thinking its not an rb30 water pump!

can i still put an M6 bolt there? can any please shed some light to this? thanks guys!!

[axe s]

If it has the 6mm hole it is an RB30 one.. i have an RB30 one on my RB25 and it isn't elongated..

I don't know about the Bigger than OEM pump.. could or could not be..

Just let your car cool down or the coolant to dry in the hole and use some gasket maker to fill the hole, they mustn't have used anything to block the hole.. i did this when i did mine because the gasket isn't very thick there and there is nothing holding it tight to the bloke..

[czar02]

thanks for that axe

so the M6 hole on the RB30 pump does not line up with the block? i take it that the elongated hole would be the RB25 pump?

i would really prefer to put a bolt there but if that's the case then i'll just fill it up with gasket maker.. when the mechanic showed me the other jobs they did with the RB30 pump fitted, they didn't even filled it up with gasket maker.. i just hope their job last the next 100k..

[wlspn]

I fitted an RB30 water pump to my RB25DET as there was a huge price diff & the only change was the bolt hole you mention.

I was going to file out the hole in the 30 pump to elongate it but there wasn't a heap of material there so instead I drilled & tapped a thread in my block that lined up with the hole in the 30 pump. Am surprised your mechanic didn't just do that...

There is a fair distance between the original thread & the new one so now I can run whichever pump I choose with all the bolts in it.

I have heard many people leave the bolt out & fill the hole with silicon but seems a bit risky to me. Can't be bothered doing the job twice...

[czar02]

how much price difference is there between the RB25 and RB30 water pump?

yeah it would've been nice if my mechanic did that but i guess he's confident that it wont leak and just leave the bolt out.. just for peace of mind, i'd rather get the RB25 pump.. im thinking of getting the 100k service even though it's only done 75k since the last one.. but also thinking of going to a different mechanic..

[koduRB25det]

hi guys!

my water pump is leaking coolant in the #1 hole of the water pump which is where the M6 bolt goes in.. 100k service was done at start of this year and only noticed it last month that there was no bolt on the M6 hole..

my question is, what is the difference between the rb25 and rb30 water pump? i've also looked through pictures online and they seem to be similar and the rb30 can be fitted on an rb25de engine..

i went to the mechanic today and showed him that there was a bolt missing on the water pump.. he told me that he fitted a 'high performance' rb30 water pump and it was bigger than the OEM water pump.. he didnt include the M6 bolt because the holes don't line up.. he also showed me some of the works he's done in his workshop with the M6 bolt not fitted..

the M6 hole on my water pump is not an elongated one found on the rb30's.. and got me thinking its not an rb30 water pump!

can i still put an M6 bolt there? can any please shed some light to this? thanks guys!!

RB30/RB20 they fine with RB25det. dont warry too much about M6 bolt [ use some gasket maker and seal it up]. but the probluem is they wont last long with rB25det [APx 10000 - 15000 km] I fit RB30 water pump to my R33. no prob. price wise they big difference. but if you can buy RB20 genuine one that should be fine with ur RB25. RB20 genuines are lot cheaper than RB25DET.

[bubba]

Isn't the pump with the elongated hole an N1 pump?

I'm running an OEM RB20 pump on my 30, bolted up fine with no fudging around.

Edited November 16, 2010 by bubba

[czar02]

i really don't want to just seal the hole, but for a quick fix i'll just fill it up with gasket maker..

my understanding with the N1 pump is that, its got a less fin compared to the RB25's & RB30's.. i read too that its best use for track, street wise is not so good.. but i could be wrong..

[tridentt150v]

RB25 pumps are around $200 [last I looked on ebay], RB30 pumps are $60 or so. I have an RB30 on my 25 and have no issues so far, but will drill and tap another hole next time we replace it.

[B-rice]

Sorry to revive old thread. What are the differences in flow between these. I have a 25/30 and it's leaking from the top of the water pump. Ive heard about RB30 pumps not flowing enough for 25/30. 

If I was to tap a hole for the extra bolt. Do I go into an oil or water jacket? Is it possible to do this without going to a jacket?

[tridentt150v]

Can't help you...I ended up having to replace the pump, but this time round I purchased a proper RB25 one [well a non RB30 one anyway].

Did the belt, idle wheel, tension wheel and such at the same time.

[KiwiRS4T]

On 16/11/2010 at 9:35 PM, tridentt150v said:

RB25 pumps are around $200 [last I looked on ebay], RB30 pumps are $60 or so. I have an RB30 on my 25 and have no issues so far, but will drill and tap another hole next time we replace it.

They must have got cheaper - around $100 now from Nissan:

http://www.trademe.co.nz/motors/car-parts-accessories/nissan/engines/auction-1323409469.htm

[tridentt150v]

Life just gets better and betterer!!!!  I can't remember what I ended up paying for mine....but I got a belt kit at the same time so it was all lumped in anyway.