Tuesday, April 2, 2013

Swapping a Rotted Radiator

A couple of weeks ago on a Saturday morning I was doing my usual fluid top-up when I noticed a small crack across the top of the stock radiator. This is the radiator that originally came with my truck way back in 2001 manufactured by Harrison for GM. The crack was about three inches long and had some signs of oozing, even though I hadn't yet smelled any coolant - I knew it was a matter of time.

I started calling around and found an after-market radiator for about $300 - this one was in stock so I got to look at it and basically passed as it was cheaply made. I toyed with the idea of getting one of those fabulous all-aluminum radiators custom-made by Ron Davis but wasn't ready to spend the $600 or so plus shipping. Looking around on the VX.info forum I found a post for a $67 radiator from an eBay seller with free shipping - from the photos it looked the same as the one I found locally (even the numbers looked the same - the only difference I found was the distributor name, the eBay was from "Sunbelt Radiators"). I decided to bite the bullet and try out this cheap thing, figuring that if it didn't work I could always get the Ron Davis upgrade. Surprisingly, the radiator was waiting for me on the front stoop 2 days after I ordered.

Overall the radiator was well packaged and came in good condition. The plastic at top and bottom appeared to be a little lighter than the Harrison but wasn't flimsy. The whole unit when compared to the original is a bit lighter but that may just be residual liquid adding weight to the old. One identifier is the way the return tube bends down more on the aftermarket (more photos with a side-by-side later). A couple of other things - the after-market is exactly the same size and thickness, however the bottom slots for the fan shroud are shaped differently (they're wider, presumably to be more generic). Also, the stay for the overflow tube at the top is in a slightly different position and the slots for the shroud nuts at the top aren't as tight (the nuts will fall through). I wanted to make sure that this radiator would work before peeling everything apart so I spent some time doing additional research online and after a few weekends felt fairly confident that I could make it work.

Next, I decided to peel apart the front - this was also to solve an issue I was having with one of my aftermarket fog lights, but also to make it easier to take off the front skid plate (it allows for more room when removed and a bit less mess as the draining radiator doesn't empty into it).

I also spotted a couple of bolts that had backed themselves out - this was on the center bumper support (actually right behind it) and figured they were responsible for one of the rattles I sometimes hear, so I removed the support and tightened the bolts.

There was one other issue I wanted to address while I had everything apart - those red silicon radiator hoses I installed back when I did the timing belt had an issue - the bottom of the passenger side hose would occasionally swell and flex with heat and rub against the alternator pulley - I wanted to inspect and possibly replace the hose so I had a back-up on hand. Here are some photos of the damage I could see.


 You can see from above that my temporary solution was to zip-tie the hose to the top of the radiator so it wouldn't flex and rub (real bogus engineering there folks).

When you disconnect the tranny cooler lines plug the ends with those squishy, disposable ear plugs - they'll save you from a lot of mess. Here's the original radiator...

 Make sure you keep the two bottom bumpers when you lift the old radiator out - the provide a much needed padding to prevent the radiator from bottoming out on the front frame support. Also, you'll need the radiator cap and the two transmission flexible lines (you can see the earplugs in the ends in the photo above). You'll also need to carefully scrape off the two rubber moldings from the sides and reapply them to the new radiator (they prevent the sides from rubbing in the metal frame). Here's a comparison of the two side-by-side:

After examining the rubbed hose I determined that there wasn't any softness - the pulley appears to have only worn through 2-4 layers and there was still plenty of silicon in the hose wall.

I decided to re-use what I had - I've been trying to get a replacement but haven't met with any success, even when offering to pay for the hose. The other problem was the culprit of the hose running - I determined that the hose was a bit over an inch too long.

I carefully marked the excess and cut off with a razor knife...in retrospect I wish I had done this comparison when I did my timing belt - live and learn I guess.

When trying to pry out one of the retaining nuts for the fan shroud at the top a whole chunk of radiator broke off. This stuff is extremely brittle - looks like recycled plastic to me and deserves more of an inspection (recommend you do occasionally if you still have the original).

After reapplying the side rubber moldings I placed the new radiator in its new home. I used some double-stick tape I got at Harbor Freight, the 3/4 inch wide stuff, placing it on one side then razor-ing off half which can be applied to the other side. This stuff works pretty well.

The top bracket was a little "loosie-goosie" so I put a thin piece of foam padding under between it and the rubber pad. One trick to getting the nut on those bolts is pull the shroud away from the radiator, insert a nut with your finger under the bracket (so it doesn't fall through), thread the bolt loosely then flex the shroud under the loose nut on both sides. Then tighten as usual.

The two halves of the fan shroud were also loose so I added a self-tap screw on each side to maintain it's shape. I'll replace these with stainless screws at some point but these will work for now.

This is what it looked like with the hose shortened and installed...much improved from the previous install.

After putting the motor and all the lines back together I fired her up and waited for leaks - it didn't take long to spot leaks coming from both tranny cooling lines. At this point it started to get dark (that was Saturday March 30) so I called it a day. In the morning I inspected the leaking areas - seems the diameter of the tubing is slightly smaller than the hoses - also, the plastic overflow tube was loose, so I added some 3/8 inch diameter hose clamps....

I continued pouring in coolant and massaging the top hose until all the air was out of it and basically waited for the coolant to expand, all the while looking for leaks. It all looked good. I killed the engine, checked everything again and then shot this video.

Afterward it was a matter of re-filling the transmission with fluid (quite a messy job), securing the hose with an extra thick zip tie (need to order the proper hose retaining clip) and completing the assembly of the front - I did manage to find the short in my fog lamp and fixed it too. The whole job took about 6 hours on Saturday and another 6 hours on Sunday, so it may have been worth having it done instead of doing it yourself. I guess it depends on whether you like doing this stuff or not.

-- John

Sunday, April 22, 2012

About Time for a Timing Belt

I replaced my first timing belt at around 70K miles. I just edged over 150 and figured it was about time for my second. In preparation I decided to try one of the inexpensive kits offered by several dealers on eBay. In my case, the kit was "on sale" for around $130. The kit included the water pump, tensioner pulley assembly, idler pulley and a good aftermarket belt. All the parts were Japanese or Korean. Doing some research I decided to use the excellent instructions available from VX owner Bart on the vx.info forums: nfpgasmask here: http://isuzugeek.org/howtos/tbelt/tbelt.htm. He made some additional recommendations so I purchased a new tensioner and a new water pump stud (got those from Merlin at St. Charles Auto: 1-800-727-8066). Since the serpentine belt I had on it looked decent, I deferred on that (it's easy to change anyway).

I had also decided that while I was in there I may as well upgrade the radiator hoses to silicon - I purchased these from SVX Motorsport ($140 Plus shipping: http://svx-motorsport-accessories.stores.yahoo.net/pusiraho2.html ). I also purchases some excellent Stainless Steel Constant torque hose clamps from a dealer on Amazon: http://www.amazon.com/dp/B0002QTK1C/ref=pe_175190_21431760_cs_sce_3p_dp_1)

I decided to take a couple of days off from work - had a week left over from last year plus I wanted to be able to access any parts stores if I ran into an issue - since most are closed on the weekend it's just easier when things go South. I put together my tool kit and parts and headed outside about 10:00 AM. Here's a couple shots of the VX before I started.

Here are the parts from the eBay kit:

Japanese-made idler pulley
Korean-made tensioner assembly
Not sure where it's made, probably Taiwan
Brazilian-made water pump
Some general impressions - the pulleys both seemed to be of good quality - time will tell. The belt also seemed very well made as did the water pump. It did have cast fins instead of the bent-steel of the original - also the gasket was paper instead of the original metal. I figure that if something goes wrong I'll just take it apart and use real OEM - I'll only be out the $150 and since the VX has a non-interference engine there isn't too much risk of damage.

Here are the OEM parts I used:

And here are a couple of extras (the thread-lock is needed for one of the bolts in the water pump):

New pure silicon hoses and clamps:

Tools, consumables and the drip pan:

These are the dissembly photos:

Sans Serpentine belt

So here is when things got interesting:

When you pull off the old timing belt, the cam pulleys are supposed to move inward to the 12 o'clock position (according to Bart's excellent guide) - instead mine went to the outsides:

Right Cam Pulley

Left Cam Pulley

I continued with the dissembly:

New water pump, stud and idler pulley on the top and right
Tensioner Pully Assembly on the left

So now the first problem. Take a close look at the tensioner pulley assembly on the left. That's actually the original assembly with a transposed pulley. When I compared the original to the replacement it was quite evident that the offset (distance from the front of the motor to the inside edge of the pulley) was incorrect. There's a difference of about 4 or 5 millimeters - no way the belt would have tracked right using the replacement. I ended up taking both to the bench and using a vise to hold things down, removed the pulley - luckily the inside shaft had the same diameter so I went with the new pulley instead of replacing the old.

So at this point I called it a night and posted a question about the cam pulley placement on the vx.info forum. I also took another look at the videos available there regarding the timing belt. Some helpful guys chimed in and I decided to go for it, cranking the cam pulleys inward instead of outward. The opinions were that it shouldn't matter as long as everything lined up.

The next morning I took a look at the belt and came to problem number two with the kit. OEM timing belts have two marks (one for each cam pulley) and a dotted line that you align with a notch on the back of the drive pulley. This "ITM" belt had four marks and none of them lined up with anything - also the marks were on the "gum" side of the belt instead of the edge of the "tooth" like and OEM belt. I selected one of the marks as a reference, placing some blue painters tape next to it to indicate where the tooth was and counted to the next mark (53 teeth for reference) - there I placed a mark with a sharpie and a piece of tape with arrows:

Right Camp Pulley Mark
I then counted to the next line on the original (71 teeth if any one's interested) and placed repeated what I did for the prior. Just for piece of mind I counted to the dotted line and they were the same from both both belts, so I knew the belt was the proper length. I then went back to Bart's directions:

Right Cam Pulley with everything lined up

Left Cam Pulley with everything lined up

Drive Shaft Pulley Lined up

So here it is with the belt completed and the tensioner released. I spun it a couple of times to make sure the marks and pulleys lined up (you lose the marks on the belt) and everything looked kosher.

There were a couple of parts that were a bit rusty that I first cleaned off with mineral spirits and then shot with Rustoleum:

Repainted Skid Plate
Drive Pulley
Finally I put everything back together:

And added the new hoses, reconnected everything and filled the radiator:

Here's a video I shot of the VX when I first tried the ignition with the new bits...

What you don't see in the video - after another minute the Check Engine light came on - doh! Got out my reader and it was showing a P0104 code - something about a lack of air pressure on the MAS - got out and checked the connection and of course I had forgotten to attach. Did so, cleared the code and the VX was ready to go.

Finally reassembly took about another hour - I took time to clean everything off really well, especially the radiator and areas behind the cladding. I waited until the next day for the test drive since I wanted to top-up the tranny. I ended up losing a lot more ATF that I expected - needed more than a quart to get it topped up.

Here's a couple of photos of the actual tools I ended up using:

Used the impact wrench to remove the drive pulley

In all the entire experience wasn't bad, especially since I took my time. I think this will be the last time I do any major repair like this myself - my back was really sore after each day from bending over the fenders and front - guess I'm getting too old for this kind of thing. The other thing - some of the torque settings seem really lighter than they need to be - the water pump for instance. I wanted to over-tighten the bolts as they just didn't seem to be very tight - if anything fails it'll probably be due to my going an extra half-turn...

For reference, the seller of the kit I purchased on eBay:

Item Title: 99-01 3.5L Isuzu Vehicross Timing Belt Seals Water Pump
I purchased on 5/22/2009 (yeah I know it's been a while)

The part that was incorrect:
Roller Tensioning Bearing
Box is marked: GMB Tensioner & Idler Bearings
Made in Korea
Belt Tensioner 8-97116-002-0!

I'm not sure if the seller put the wrong component in the box or if the kit was just mis-configured but thought I'd share the numbers in case the kit is still wrong. Here's a link to a current auction for the equivalent on eBay by the same seller:

It's now Sunday so I've run the VX several times without any issues. I'll report if there are any failures, etc.

-- Best, John