986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Sanity check - my coolant went about a quart low after WP/Thermostat change

steved0x · 01-12-2015, 11:14 AM

I just finished up a water pump/low temp thermostat/UD Pulley last night and this morning I took it for a drive. About 15-20 minutes out the coolant light starting flashing slowly and the temp stayed right on the 1 part of the 180. I was staying close to home for the test drive so I immediately came in, and found that the coolant was about a quart low. Trunk was dry and no gushing out by the back wheel. I added about a quart to top it off, and took another 20 minute drive, during which the level stayed full and did not drop, and my light did not flash.

I used the Airlift vacuum tool to add my coolant but I am thinking that maybe a small quantity of air remained in the system and burped its way to the top (I did not do any bleed procedure after filling the coolant with the tool). Should I flip the bleeder valve and go for another drive, park nose down, all the tricks I have seen for bleeding (including following the Bentley procedure

) to make sure I have gotten all air out?

When I used the airlift tool I took it up to 25 on the dial (per the instructions) and let it sit that way for a few minutes, during which time I lost no vacuum and the reading held steady. I know that vacuum is not the same as a pressure test but I felt pretty good about that.

What do you guys think? Leak some where? Or just a little air in the system that came to the top and dropped my level, hopefully as a one time thing?

Thanks

Steve

PS For a data point my waterpump was the original pump (2000 Boxster 115,000 miles) as evidenced by the fact that I had to cut the three metal webs in order to get the old gasket off. Vanes were intact and there was no play in the bearing. It did spin just a little easier/faster than the new pump. On the inside it looked brand new, and the outside was pretty good too. I feel like I got a good life out of it, but since I had no record of it ever being changed I figured it was time.

Two of the water pump bolts are longer than the others. The water pump comes with 2 dowels to help align it and also you can pop the gasket onto the dowels and the dowels hold the gasket as well as to align the pump. The two longer bolts go with the two holes that have the dowels. I was paranoid when starting the job to make sure I got those two bolts back in the correct spots, but once the pump was off it became apparent. I was able to torque every bolt except the rightmost one, so I just tightened it nice and tight by feel.

01-12-2015, 11:14 AM	#1
steved0x Registered User Join Date: Dec 2012 Location: FL Posts: 4,143	Sanity check - my coolant went about a quart low after WP/Thermostat change - air? I just finished up a water pump/low temp thermostat/UD Pulley last night and this morning I took it for a drive. About 15-20 minutes out the coolant light starting flashing slowly and the temp stayed right on the 1 part of the 180. I was staying close to home for the test drive so I immediately came in, and found that the coolant was about a quart low. Trunk was dry and no gushing out by the back wheel. I added about a quart to top it off, and took another 20 minute drive, during which the level stayed full and did not drop, and my light did not flash. I used the Airlift vacuum tool to add my coolant but I am thinking that maybe a small quantity of air remained in the system and burped its way to the top (I did not do any bleed procedure after filling the coolant with the tool). Should I flip the bleeder valve and go for another drive, park nose down, all the tricks I have seen for bleeding (including following the Bentley procedure ) to make sure I have gotten all air out? When I used the airlift tool I took it up to 25 on the dial (per the instructions) and let it sit that way for a few minutes, during which time I lost no vacuum and the reading held steady. I know that vacuum is not the same as a pressure test but I felt pretty good about that. What do you guys think? Leak some where? Or just a little air in the system that came to the top and dropped my level, hopefully as a one time thing? Thanks Steve PS For a data point my waterpump was the original pump (2000 Boxster 115,000 miles) as evidenced by the fact that I had to cut the three metal webs in order to get the old gasket off. Vanes were intact and there was no play in the bearing. It did spin just a little easier/faster than the new pump. On the inside it looked brand new, and the outside was pretty good too. I feel like I got a good life out of it, but since I had no record of it ever being changed I figured it was time. Two of the water pump bolts are longer than the others. The water pump comes with 2 dowels to help align it and also you can pop the gasket onto the dowels and the dowels hold the gasket as well as to align the pump. The two longer bolts go with the two holes that have the dowels. I was paranoid when starting the job to make sure I got those two bolts back in the correct spots, but once the pump was off it became apparent. I was able to torque every bolt except the rightmost one, so I just tightened it nice and tight by feel.