ZeeOwe6

So I took the ol girl (02CZ) to town and she was just loving the cold weather today. Ran her pretty good in the upper 5k - low 6k rpm range through a couple gears but didn't flog it to town and back. there were no puddles or dribble trails anywhere till I parked it at home. went back out the garage and could smell hot antifreeze. looked under the car to about a 1/8th of a gallon on the ground. looks to me like its the rear seal behind the water pump or I just blew up the WP....how difficult is it to change this? looks like there is a lot of stuff to remove.

racebum

it's easy, you will also want to replace all the hoses when you're in there. good chance to clean the radiator too. do not over tighten the WP bolts

list of all your part numbers in the cooling system and aprox. prices, there is probably a lower cost hose for part # 10229491 by dayco/goodyear etc. also buy your 5/8" heater hose somewhere local and get the smallest 5/8" they have, bring a caliper, some measure 9/16 which is what you want, some measure TTS at 10/16 or large at 11/16, you don't want this

Ac delco 20889 radiator $188.16
Ac delco water pump 251-744 $177.61
Ac delco water pump inlet w/ stat 15-11057 $29.30
Ac delco 18021L hose $27.52
Ac delco 24388L hose $25.35
Ac delco 24458L hose $14.59
GM hose 10229491 $24
Gates 18127 $12.62
Gates 5/8” heater hose {runs small} 2ft section
GM coolant tank 10430189 $69.95

Last C5

It's not a bad job. It'll take you longer to drain the radiator and clean up the mess from disconnecting the hoses than the actual replacement of the pump will take.

racebum

there's one hose clamp that's a bear if you don't have cable hose pliers too, might be the upper one, can't remember, just remember trying all kinds of nonsense to get it off and wondering why i have never bought cable hose pliers. was hard to get conventional tools on it

ZeeOwe6

Thanks for the reply guys... just for effect. here's how bad it is. runs at a trickles pace. Id load a video, but the forum doesn't support quicktime:/

racebum

you can upload videos to youtube and link that way

fix it before it gets worse, you also will need to replace your belts and really clean the pulleys, if they aren't squealing now they will soon from slipping on the coolant

ZeeOwe6

theres no doubt that it has to be fixed. it wouldn't make it a mile without over heating and damaging the engine. im not sure how I didn't have a trail down the street or puddles else where. This is not a daily driver so it sits where it does till its fixed. parts are on order and should be here Thursday. already have another belt ready so just a cleaning and radiator hoses to be changed and I will be back in business.

racebum

you have two belts, an ac belt and the main belt. would also suggest dayco or goodyear, they have plastic molded in the belts that's less prone to squeal than the more rubbery gates. just an ls1/ls6 thing

make sure you use some purple power, dish soap etc and scrub the hell out of the pulleys, then hose the bejesus out of them, let them dry, then install the belts. do this step last as you will get coolant on stuff changing the pump and hoses

i wasted 2 belts my first time doing this job before i realized how sensitive these engines are to belts and contamination - slippage

ZeeOwe6

the good thing is that it only started leaking after I shut it down. there is not any antifreeze on the belts, just on the crank pulley. I have the main belt guess I only need the A/C belt and a little cleaning.

ZeeOwe6

Ok got the old pump out... What a pia! Biggest mess I've ever made changing a WP. Lol. I got to looking at this and I can't find where it was leaking. All seals look ok and opened the pump and all was working. Got the other parts off it and On to the new WP... Any famous last words before I install?

neutron82

lol, the first waterpump I did I drained the radiator and tried my best to keep it clean but that didn't work... now I just say F it and pull it off and let it go everywhere haha... I just put a couple of drain pans and a bunch of cardboard boxes under the car to keep it off the garage floor

racebum

make sure everything is very clean. sand with 1500grit sand paper if you see any rough spots, do not over torque the bolts

now you see why i said to clean the pulleys so well, makes a giant mess

also blow out your radiator while you have this apart and easy access with an air blower

ZeeOwe6

OK heres the pumps...what a difference. wonder why the new one is sealed and the old WP is serviceable? still cant find where the pump seal failed. there was a little moisture on the left side from the rear of the pump but no signs of a blow out...hope is not the seal on the intake! digging deeper this evening.

racebum

if you filled the pump up with water and added 15psi of air, then spun the pulley you may see it

if you can't do that, it's just a reasonable guess.

water pumps at this age are a very common failure item, VERY

ZeeOwe6

Houston, I have a problem. new WP IDA is smaller than the stock WP IDA opening for the Thermostat...I ordered stock replacement parts and this is what I got.

racebum

i mentioned this in the part numbers i listed above

you need the updated state and outlet

ZeeOwe6

my bad I must have over looked that...ended having to go to the Stealership today and for the correct one it cost me damn near the cost of the pump. $78 later im back on the road looking for birds and ponies for lunch.

now its time for a complete engine bay wash down with a heated pressure washer and some degreaser before winter hibernation.

racebum

yikes, they were only 29 shipped on amazon

ZeeOwe6

Yea, I know. Just got sick of looking at the Z with the hood up and a massive mess on the floor.

neutron82

interesting, so with the delco pump you listed above the original thermostat/housing won't fit?... my pump is off right now while I'm doing some other things and I considered replacing it just for good measure since it's kind of a pain to take off now having a blower in the way but I don't really want to have to buy a new thermostat and housing, mine is almost brand new anyway... I noticed on rockauto they have 2 delco pumps, one with the housing already installed which is cheaper (252836) and a more expensive one that doesn't include the housing (251744)... I was going to buy 251744 and reuse my thermostat