Could anyone help me with, How to loosen the belt tensioner on my 07 Aspen, 4.7 flex engine. My water pump started leaking and I,m thinking about replacing it myself. After looking at the pulleys etc.I can't see how to loosen the belt in order to remove the pump. The Old days, generally loosen the alter. or pulley. Any help or suggestions will be appreciated.
Thanks

 

spring loaded tensioner

 

While on the subject of water pumps.... mine is leaking as well (5.7L motor). What has to be unbolted and moved out of the way to get at the water pump properly for removal. Looks pretty tight in there without pulling at least the fan shroud, any other tips? Thanks.

 

pretty straight forward get a manual and it will tell u what needs to come off.

 

Any special tools needed?

 

If you have the hemi you will need a pin spanner wrench to hold the water pump pulley while you undo the large nut for the fan. I'm looking to do the same job and noticed today that the leak is gone, bone dry. I'm guessing that intermittent leaks may be typical before a major failure but if you are familiar with water pump behaviour please advise.
Looks like 4 1/16" needed between the pins and about 28" of square metal tubing cut in half so you can mount the pins (bolts) and brace the spanner wrench on the frame as you use a crescent with a snipe to undo the large nut behind the fan. Turn the large nut clockwise to loosen, as you are standing facing the front of the engine. The manual doesn't tell you this. I tried a few bolts in the water pump pulley holes but didn't write down the size, sorry. The bolts will have to be approx. 3" long and threaded all the way so you can fasten to the tubing with nuts or if you are a welder then weld then on.
You'll have to drain the coolant first. After you get the fan nut loosened, undo the bolts for the shroud as the fan and shroud have to come out together through the top. Be careful not to hit the rad fins.
Going to tackle this in the next few days so if anyone is interested let me know other wise I will let this thread die due to lack of good dialogue or interest.

 

My mistake, measurement between the pins was 3 1/16" not 4 1/16". Bad old habit from carpentry and measuring from the 1" mark. I just made up the pin spanner wrench today. The brother-in-law said to use grade 8 bolts or better as I will have to apply quite a bit of torque to get the nut loose. It's one of those days.... bearing in the house furnace is going and my BAS and traction control lights came on today on the Aspen when I moved it into the garage and all I thought I had to do today was change the waterpump. When it rains it pours.
Wish me luck.

 

Changed the water pump out on the 07 Aspen with hemi and here's a few tips and tools needed to get the job done that they don't always spell out in the manual.

- I drove the vehicle up on 3" blocks for height. Let the engine cool and disconnect the negative terminal of the battery.
- pull the airbox out and associated plumbing for access
- drain the coolant from the rad via the plug at the bottom, I got about 6-8 litres in my pail. That is all the draining needed.
- disconnect the upper rad hose. disconnect the lower rad hose from the bottom first and try to slip it slowly off the rad connection with a pail to catch that last few cups.
- undo the heater hoses from the water pump on the passenger side.
- take off the serpentine belt via loosening the tensioner with a 3/8" drive - I used a ratchet, turn clockwise to loosen. Take off the belt tensioner – 15 mm.
- install the pin spanner wrench from the driver's side from underneath. Place it over the power steering cooler lines and brace it against the frame. Takes a bit of finagling.

- from the driver’s side get a crescent wrench on the large nut and use a snipe (I used a large pipe) or wrench over wrench to turn the nut counter-clockwise (this is now correct) when facing the engine from the front.
- once the nut is loose it's a lot of wrench quarter turns with the pin spanner in place to get the fan off. Last few turns can be made by hand and should be made by hand so you don't drop the fan into the rad. Once loose lower the fan down. Undo the bolt for the fan shroud on the driver’s side (only 1 bolt) and push the other side out of its hole and pull the shroud and fan up together removing the fan once it's clear of the compartment. Then the shroud pulls out too. Don't force the shroud as I broke mine and had to repair it. Yes you need the shroud for cooling to work properly.
- Make a bolt pattern with the new pump on cardboard and place over a box. Poke holes for the bolts.
- remove the small plate above the water pump by taking off the 3 nuts and one bolt. This plate covers access to some of the top water pump bolts.
- As you pull the water pump bolts out place then in your pattern, they are different lengths (13 and 15mm heads)

- Pull the old pump off, some coolant will come out.
-Scrape any junk off the block and clean up with paint thinner and wipe dry.

- Clean up the bolt threads
- Attach the idler puller and bolt beside it (first) and thermostat and housing before installing on block.

-Install the gasket, I didn't use any sealant and have no leaks.
- Place the new pump on carefully and hand tighten all the bolts and then torque to 20 lb-ft (I used a lb-inch wrench at 230) in a criss cross pattern like a rim.
- connect the heater hoses
-install the belt tensioner pulley
- put on the serpentine belt

- place the pin spanner wrench in the water pump pulley holes but from the passenger side from underneath and brace against the other frame rail.
- slide the bottom of the shroud in and then the fan. Side both down into place and thread the fan nut onto the water pump. I pushed the fan in towards the pump and used the crescent to thread it on. Maybe you can do it by hand to get it started to avoid any cross treading. Once the nut is as tight as you can get it with the wrench only use a short snipe and the crescent from the driver’s side to apply that extra push to get it tight.
- Install your rad hoses and tighten up the fan shroud bolt.
- Filter your coolant if reusing, I did as I had just flushed and replaced coolant last fall. I got about 4 litres back in (1 gallon) before the rad was full.
- reinstall air box and reconnect battery and fire up the motor. I had an airlock so released the rad cap slowly and added coolant until it was full. Tried running it with the rad cap off but it just poured coolant out.
- check for leaks. I had poured water to clean coolant off the block and parts, wiped dry and then took my compressor and air nozzle to blow off any residual.
- test drive and watch the temp gauge and check for leaks again.
Good luck if you have to do this and hope it helps at least one person. If I missed something please use constructive criticism so it helps others as well.


Pin Spanner wrench:
made from a chunk of 1" square tubing cut in half, you can use anything solid and strong. I found that 28" long was the right length for the wrench for bracing on the frame. I used 1 3/4" number 8 bolts, 3 1/16" apart. Anything longer in there might not work as it’s tight with the 1 3/4" bolts. Use washers and nuts to tighten on the handle. Use the belt tensioner to help align the bolt holes for both the loosening and tightening using the pin spanner.

Snipe for the crescent was a piece of galvanized steel from an old fence.

 

Here's a few more pictures that I couldn't get on with the first post. Let me know if it helps.

 

Whoops screwed up on the direction to loosen the large nut, should be counter-clockwise when facing the engine from the front. Clockwise to tighten.