Jump to content
Sign in to follow this  
fiskld

Broken Cooling Fan Motor Bracket

Recommended Posts

Hello All,

While traveling through Canada on our way to Alaska in our 2005 Beaver Patriot Thunder the bracket for the cooling fan motor broke which allowed the fan to run wild. Needless to say the engine radiator was destroyed along with the cooling fan.

It is now in Kamloops, BC at IRL International Service Center getting repaired. The local radiator shop said they could re-core the rad with a brass/copper core. They also said the destroyed one was a brass/copper so it must have been replaced since I bought the coach in 2008. They also said my charge air cooler was cracked and losing a pound of air a second so it needed replaced.

Anyway what is the charge air cooler and how does it work. Is it part of the radiator? Is a pound a second a lot? They also want to "dip" the radiator in solder to make it more durable. Is this a common practice? I never heard of this before.

Thanks so much for any thoughts. This is going to be an expensive fix that I do know. Just the new core for the radiator is $3000! Wish I would have checked that bracket before I left.

Share this post


Link to post
Share on other sites

Anyway what is the charge air cooler and how does it work. Is it part of the radiator? Is a pound a second a lot? They also want to "dip" the radiator in solder to make it more durable. Is this a common practice? I never heard of this before.

The CAC (Charge Air Cooler) is an air to air radiator that takes hot intake air from the turbo (at up to 300 degrees F) and cools it to close to ambient temperature and then it goes to the engine intake manifold. Any loss of pressure in a CAC costs you HP and MPG.

Never heard of dipping the radiator in solder, so can't comment.

Share this post


Link to post
Share on other sites

Thanks for the reply, the local rad shop said it is common on logging truck radiators to "dip" them to make them more durable. I also have never heard of this but thought if it will help prevent failures then OK. It was $250 extra per side so it wasn't cheap. We're now waiting on the new bracket for the cooling fan motor to arrive. I never thought about something like this happening. Oh well, once it's repaired we'll have a new radiator, CAC, and fan. Hopefully the new bracket will keep the motor and fan where they belong. With the new CAC the service tech said I will notice a big improvement in engine performance. I never really thought it was bad but better would be good. Check your cooling fan motor brackets! If it breaks it's not good....

Share this post


Link to post
Share on other sites

Larry,

Would appreciate your posting some photos of the fan bracket failure. That would help others with the same chassis to evaluate theirs.

If no photo, please describe in detail what failed and if you/the shop have a suspected cause, please post that.

Thanks.

Brett

Share this post


Link to post
Share on other sites

Will do Brett as soon as I get to my computer that has the photos. I was pulling a hill when I heard a big bang in the rear. I asked my wife if she heard that and she did not. Things were still looking good so I kept going until the engine temp began to rise and the check engine light came on. No shoulder on the road so I stopped in the right hand lane of a passing lane just 14 miles south of Cache Creek. When I walked to the back I saw extended life coolant on the road. When I opened the back hatch to take a look in the engine compartment a fan blade fell at my feet. No service in Cache Creek so we were towed to Kamloops. So our planned trip became very unplanned and expensive. I'll be glad when the coach is repaired and we can travel again.

Share this post


Link to post
Share on other sites

Dipping the tank in solder is pretty common in the industry. My only concern is that the efficiency drops somewhat because the fins aren't as thin. It will make the radiator stronger but I don't think it's necessary in a motorhome app it's much easier riding

Share this post


Link to post
Share on other sites

Well unfortunately the photos are on my I Pad and it does not seem to work with this upload program. Yes, your probably right about the dipping being over kill. I was just thinking on roads like the Alaska Highway it might help with all the gravel sections. I didn't think about losing efficiency and it was never mentioned. I'm afraid it's already done now, just thought I would ask about this dipping process because I had never heard of it.

Share this post


Link to post
Share on other sites

Also Brett the service tech is not sure what caused the failure. He said if the blades were breaking first the vibration from the imbalance maybe caused it or the bracket broke first which broke the blades. He also said the CAC crack was not caused from this, he feels it was already there.

Share this post


Link to post
Share on other sites

Yes, the CAC is outboard of the radiator, so the radiator would have "protected" the CAC from damage by the fan.

Share this post


Link to post
Share on other sites

As you can see the cooling fan motor was hanging by the hydraulic hoses, the bracket that held it in place was gone.

post-8788-0-79846800-1339815705_thumb.jp

post-8788-0-61054200-1339815732_thumb.jp

Share this post


Link to post
Share on other sites

Thanks again Brett for helping me undertand the CAC, I had never heard of this before. I knew my fuel mileage was bad but I thought that was just the nature of a 525 CAT. The service Tech. said my turbo was running all the time because of the leak in the CAC. Now I'm wondering if the turbo needs replaced from all the running needlessly. I hate to be paranoid but I also don't want to be shutdown again on the road and wishing I had replaced it now while its in the shop.

Share this post


Link to post
Share on other sites

Larry,

I wouldn't be too concerned about the turbo. That same engine is uses in lots of trucks weighing 80,000 pounds frequently doing 80 MPH. By comparison, you are not really pushing that hard.

And from the photos, it looks like your CAC may be on top of, rather than in front of the radiator. Interesting configuration-- called STACKED vs SANDWICHED. Makes both a lot easier to clean with a hose.

Share this post


Link to post
Share on other sites

Thanks Brett, that's good to know. I am pretty ignorant when it comes to diesel engines but I'm learning with the help of people like yourself. That being said incidents like this is not the way to learn these things. Thanks again!

Share this post


Link to post
Share on other sites

Well the Thunder is repaired. Looks like the final bill will be a little over $10,000, so beware, check those cooling fans!!

Share this post


Link to post
Share on other sites

Well, I was checking out the repair on our Beaver with the engine running and I noticed the cooling fan appears to wobble just a little. I was wondering if this is normal with the plastic fan or if this could be an issue. The repair shop sent the hydraulic motor to a shop to check it out and it checked out great, no bad seals and the shaft proved true. Any thoughts would be appreciated. The fan is new.

Share this post


Link to post
Share on other sites

Larry,

Thinking that it might be out of balance.

One might be able to check the balance with a balance device used to check lawn mower blades, the cone might be big enough to work on the center hole of the fan if it has one.

Garages have stick on wheel weights for the alloy rims that might work to balance the fan.

A small balance issue could cause some considerable vibration / That might have been an issue with first the failure. With the speed changing with the amount of cooling needed, there could be a harmonic vibrations that can cause higher stress at unknown RPM.

Rich.

Share this post


Link to post
Share on other sites

Rich,

With the centrifugal force generated by the spinning fan blade and the fact that many plastic fan blades flex with change in RPM, I would be hesitant to use a stick on weight. At high RPM that would make quite a projectile.

If it is just a little out of balance, I would be tempted to just file down the very end of the heavy blade(s). If REALLY out of balance, I would drill a small diameter hole near the end of the light blade and install a very small stainless steel bolt and nylock nut. With a balance checker like you describe, you could move the bolt and nut around to different blades/further in and out the light blade to determine the exact location for perfect balance.

Brett

Share this post


Link to post
Share on other sites

Good point Brett! I was thinking that one might place them on the inner hub if the molding has one. Inside edge to off set the centrifugal force. The temperature rang on the adhesive has to have a wide temperature range considering how hot things get under heavy braking.

I would be a little concerned about drilling holes in the plastic as it might cause a point for a stress fracture line. All thought they drill holes in privet aircraft to stop further cracking in windows.

The removal of material to balance the fan(s) is a good thought. I just wish that manufactures would put good metal in areas like the fan bracket. Plastic will dry out over time and fans blades coming apart is never good !!

Glad this item came up, when I cleaned my fan last it looked like it was time to replace it. Nicks and dings in it.

Rich.

Share this post


Link to post
Share on other sites

A bit of clarification on where the wobble orignates is important. Is it only the blades, the mount, the motor? What is actually moving and does it appear to be doing the same thing at idle as well as the higher RPM's?

Share this post


Link to post
Share on other sites

Thanks so much for the suggestions. I measured each blade from the end to the edge of the shroud. Three of the blades were 1/8" different from the rest. There doesn't appear to be any vibration, It flows along pretty smoothly. Nothing is rubbing, do you think 1/8" is enough to worry about? Thanks again!!

Share this post


Link to post
Share on other sites

Larry,

Did you measure the blade to shroud clearance at exactly the same place on the shroud. Would suspect there to be more variance in shroud than blades.

And, if no vibration, it may be that they balanced the blades exactly the same as I suggested-- by shortening the heavy/heavier blades.

Brett

Share this post


Link to post
Share on other sites

Yes I did Brett. Three of the blades were 1-3/8" to the edge of the shroud, the rest were 1-1/2" to the edge. I tried to make sure I was at the leading edge on each blade and at the same point on the shroud. It looks a little more exaggerated with the eye while the engine was running, but that is what the measurement was when I checked each blade with a tape measure. This was from the leading edge of each blade horizontally to the shroud, not length clearance, but side clearance. Hope I didn't make this reply too confusing.

Share this post


Link to post
Share on other sites

Larry,

Regarding the balancing of the Fan-- IF they are molded, there could be a difference in the thickness of the material in each blade.

So the length of each blade could be misleading. One would expect the longer ones to be heaver. However, there is always the "what if factor".

The truest way would be to check the balance. By using the lawnmower blade balance or the old pin through the center hole to see if the same blade always spins to the pointing down point. Should that be the case try the balance method and place some weights on the lighter ones.

That should give you a good starting point to ether remove material or find a way to securely attach some weight where needed.closer to center reduces the centrifugal force on the weight and the material in the blades should be thicker also.

Things flying off a spinning blade is not good ether.

Rich.

Share this post


Link to post
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
Sign in to follow this  

×
×
  • Create New...