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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: turbojack on November 09, 2022, 07:56:51 am

Title: How do you find all of the Air Leaks
Post by: turbojack on November 09, 2022, 07:56:51 am
I know kids bubbles. 

My HWH air compressor would only come on  maybe once a day if that.  That was until I took this last 4,443 mile, 1 month retirement trip.  A week into the trip the compressor started running continuous.  I went out and turned all of the valves off for the slides. While was doing that I found a large air leak at the check valve.  Went to NAPA and got new fitting and fixed that leak.  I was excited that when I turned the compressor back on it went and shut off.  The compressor then came back on around 2-3 hrs latter.  As the days went on the compressor started running more often.  I had turned the valve back off to the slides so I know I was not dealing with slide leaks.  When I got back home I  jacked the coach up, put supports to hold it up and went looking for air leaks.  I found 4 more fitting leaking.  I have now fixed those but the compressor still wants to run about every  1 1/2 hour.  I am going to go back under today with my bubbles and see if I missed any locations.

Middle of the night while I was thinking where I could have missed some fitting it hit me that I may also have a check valve(s) that are leaking.

Without taking them out and testing, is there a good way to find out if they are leaking?  I have heard some talk about having some electronic detector that helps finding leaks.  Would that detect a check valve leaking? Are they as good as or better then bubbles for the fitting leaks?  Do they work if you have  some hearing lose?

The only reason I think I started having all of these leaks is the coach has been in 100 degree weather  and we went up north where it would go to freezing at night.  I have no other idea why so many leaks all at once.

For those wondering, I have never gotten any water out  of the 5 tanks.  I replace the air dryer ever other year.
Title: Re: How do you find all of the Air Leaks
Post by: Tommy D on November 09, 2022, 08:03:40 am
For the two front tanks check valves, air up completely and shut down coach.  Open wet valve tank and check your dash gauge.  If they are going down your check valve(s)  are leaking on that/those tank. Keith Risch showed me that when mine were leaking.  I think they will stop at 60psi?? Because of the regulator??
Title: Re: How do you find all of the Air Leaks
Post by: craneman on November 09, 2022, 10:25:00 am
They should stop at 60 psi. if the protection valves are working.
Title: Re: How do you find all of the Air Leaks
Post by: Pierce & Gaylie Stewart on November 09, 2022, 10:30:22 am
Buy a $1 spray bottle from your local dollar store and order the German bubble stuff from Amazon. It makes huge and long lasting bubbles. It's a huge party favorite for kids and adults alike. $8 for a big bottle here: Amazon.com: PUSTEFIX 16.9 oz Refill Bottle of Pustefix Liquid Bubble Blowing... (https://www.amazon.com/HQ-Kites-Designs-505415-Pustefix/dp/B0010MJ95O/ref=pd_day0fbt_img_sccl_1/130-1789407-8990947?pd_rd_w=MKR6R&content-id=amzn1.sym.225af909-a644-4665-9f15-c780ebd0c7cb&pf_rd_p=225af909-a644-4665-9f15-c780ebd0c7cb&pf_rd_r=TFVHVYJCDSB27AKP1V34&pd_rd_wg=yGojb&pd_rd_r=641391f5-3af4-4f68-bce1-f12db82928e7&pd_rd_i=B0010MJ95O&psc=1)

Pierce
Title: Re: How do you find all of the Air Leaks
Post by: OldManSax on November 09, 2022, 10:35:00 am
I am fortunate to have a high dollar ultra sound detector left over from my HVAC days.  I can just wave the tube around and usually detect even small leaks fro a few feet. It's more difficult to detect internal leaks but it can be done. Other than that, I use kids bubble blowing liquid. :D

TOM
Title: Re: How do you find all of the Air Leaks
Post by: Elliott on November 09, 2022, 10:49:44 am
I have had some leaks that no matter how careful I was, I couldn't identify with bubble solution. The only way I figured it out was a thorough understanding of my air schematic and process of elimination. In that situation, all bets are off until you have confidence in your check valves.
Title: Re: How do you find all of the Air Leaks
Post by: turbojack on November 09, 2022, 12:09:19 pm
I am fortunate to have a high dollar ultra sound detector left over from my HVAC days.  I can just wave the tube around and usually detect even small leaks fro a few feet. It's more difficult to detect internal leaks but it can be done. Other than that, I use kids bubble blowing liquid. :D

TOM

What kind of detector do  you have?  If you look at what I would  pay for someone to spend time searching for leaks I can buy the detector.  Besides I already have tons of tools and equipment that does not get used much, but is a big help when I do.
Title: Re: How do you find all of the Air Leaks
Post by: turbojack on November 09, 2022, 12:13:15 pm
Dean and I talked this morning and he gave me some ideas as to how to go about trouble shooting along with Tommy D's information.  One of the first things I am going to do is label the dump valves as to which one is for which tank.  While I am writing this I am thinking maybe remove the hose from each dump valve and add a pressure gauge.  That way I can see in one spot what the pressure is in all of the 5 tanks at the same time.
Title: Re: How do you find all of the Air Leaks
Post by: OldManSax on November 09, 2022, 02:12:53 pm
What kind of detector do  you have?  If you look at what I would  pay for someone to spend time searching for leaks I can buy the detector.  Besides I already have tons of tools and equipment that does not get used much, but is a big help when I do.
I'll be back at the shop tomorrow and will get you an answer.
TOM
Title: Re: How do you find all of the Air Leaks
Post by: dsd on November 09, 2022, 02:16:16 pm
Dean and I talked this morning and he gave me some ideas as to how to go about trouble shooting along with Tommy D's information.  One of the first things I am going to do is label the dump valves as to which one is for which tank.  While I am writing this I am thinking maybe remove the hose from each dump valve and add a pressure gauge.  That way I can see in one spot what the pressure is in all of the 5 tanks at the same time.
Understand you are seeking out internal bypassing leaks. Bubble solution will not show internal leaks. Yes the pressure gauges allows you to see changes happening internally they have the pressure gauges with the smaller 1/8" thread and i purchase adapters to easily install anywhere you want to.
Amazon.com: KOOTANS 4-Pack Brass Pipe Fitting, 1/4" NPT Female to 1/4" NPT... (https://www.amazon.com/gp/product/B07P6WM1S4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1) As a example.
Title: Re: How do you find all of the Air Leaks
Post by: AC7880 on November 09, 2022, 11:32:28 pm
Today I did dish soap with water mix, and a 1" wide paint brush. "Painted" all tank drain valves, and the 2 manifold blocks for the slide bladders.

Found a fair sized air leak in one of the slide bladder block manifolds in the basement bay.  It was on the 1/4 inch air line going into top of manifold, but on the brass fittings, not air hose. 

Disassembled, found a cracked brass fitting.  Put new fitting in place, teflon tape on each part of the re-assembly. Now zero leak on the manifold, and 12v compressor has not run since aired back up after the repair.

The dish soap/water and paint brush quickly showed the area in need via bubbles.
Title: Re: How do you find all of the Air Leaks
Post by: OldManSax on November 13, 2022, 11:02:59 am
Here is the detector I use. I have the industrial model. The transmitter can be connected to empty pipes and supplies Sounds internally. I can also check for chattering contactors, and bad electrical connections. After you use it a while, you will learn what good and bad connections, leaks, relays etc. sound like. I did not realize it is a GoPro. I don't know it it is the same company that make the cameras. Sorry this took a few days. Life is busy!

TOM
Title: Re: How do you find all of the Air Leaks
Post by: OldManSax on November 13, 2022, 11:05:09 am
Two more.
Title: Re: How do you find all of the Air Leaks
Post by: fourdayoff on November 19, 2022, 12:32:19 pm
Dan, careful with the Teflon tape on any air fittings on the coach. Small shards of tape can travel through the system and plug a small  orifice anywhere. Use paste. Jim.   
Title: Re: How do you find all of the Air Leaks
Post by: turbojack on November 19, 2022, 02:05:19 pm
I tried to find the detector that Tom has posted and I guess it has been discontinued.  I have also been told about the Amprobe ULD-420  This unit is expensive but it looks like it will be great finding the air leaks and but can also find wind noise leaks. by putting a transmitter in the vehicle and then going around the outside. 
Going to be at FOT and MOT  for Monday and Tuesday so I will ask them about air leaks  If they have this type of equipment it looks like it would make quick work of finding my air leaks that I am not able to find with the  bubbles.

I will follow up next week.
Title: Re: How do you find all of the Air Leaks
Post by: craneman on November 19, 2022, 03:15:50 pm
They have a way to pressurize the coach to find roof leaks. The same pressure would show wind air leaks with the amplifier I think.
Title: Re: How do you find all of the Air Leaks
Post by: OldManSax on November 20, 2022, 10:43:36 am
I looked online as well and can't find the detector I have either. I hope I don't have to replace mine but, if I did, I would make sure to buy one with really good headphones. I had tried other similar detectors without headphones and they just don't work as well. The phones I have block out almost all outside sound so that I can concentrate only on what coming from the detector. That feature has enabled me to find tiny leaks when others had given up.

TOM
Title: Re: How do you find all of the Air Leaks
Post by: turbojack on November 22, 2022, 09:45:43 pm
Yesterday when I got to FOT to have the coach service with 48 quarts of motor oil and replaced every filter, I asked about air leaks and how they go about locating them.  They said they had a detector to help located them and they had a special going on until December 21 of 10% off labor plus the 10% off for motorcade  on working on air leaks.  I told them to go ahead and see if they could find any.  Well they did.  Both pressure protection valves were leaking at the top  and all 4 air bladder shutoff valves were leaking.  I never though about spraying down the valves. They also found some more fitting that were leaking.  In all I spent just a little over $800.  The good part is if the HWH compressor did run I never heard it and when I went to start the coach this morning I had over 80 psi in both front and rear air tanks.  Problem solved for now.  I did not think to find out what device that they used for locating the leaks.  I am contemplating on getting the Amprobe detector incase I get leaks on the road to help me find them.
Title: Re: How do you find all of the Air Leaks
Post by: propman on November 25, 2022, 12:21:51 am
Is this the kind of detector?
https://youtu.be/NUrlrg6gTz8?t=189
(TP-9367L MARKSMAN™ II
ULTRASONIC DIAGNOSTIC TOOL)
Title: Re: How do you find all of the Air Leaks
Post by: turbojack on November 25, 2022, 08:55:37 am
Amprobe ULTRASONIC Leak Detector with Transmitter, (Model: ULD-420):... (http://www.amazon.com/ULTRASONIC-Leak-Detector-with-Transmitter/dp/B07XKDPZX1/ref=sr_1_2?crid=MLA2OF0EHS7R&keywords=amprobe+ultrasonic+leak+detector+420&qid=1669384089&sprefix=amprobe+ultrasonic+leak+detector+420%2Caps%2C88&sr=8-2)

This is the one that was recommended to me.  Amprobe  ULD-420  You can buy just the detector for around $500 without all of the accessories the transmitter.
Title: Re: How do you find all of the Air Leaks
Post by: oldguy on November 25, 2022, 11:18:01 pm
A friend told me that he gets a hollow tube, a foot or two,  3/8th tubing would work and you put
one end in your ear and the other end you use to look for air leaks and he said it works. He also said
you can find vacuum leaks the same way. Next time I have a leak I will try it. 
Title: Re: How do you find all of the Air Leaks
Post by: craneman on November 26, 2022, 01:21:44 am
I have used a medical stethoscope with the head off and hold the hose around fittings and it seems to work for me.
Title: Re: How do you find all of the Air Leaks
Post by: nitehawk on November 26, 2022, 08:14:31 am
Scuba gear. A large swimming pool. Submerge the coach. Look for leaks/air bubbles :))  :))  >:D
Title: Re: How do you find all of the Air Leaks
Post by: turbojack on November 26, 2022, 09:12:27 am
A friend told me that he gets a hollow tube, a foot or two,  3/8th tubing would work and you put
one end in your ear and the other end you use to look for air leaks and he said it works. He also said
you can find vacuum leaks the same way. Next time I have a leak I will try it. 
My wife heard air leak in the front storage compartment. She told me about it  I went in the compartment and could not hear it. It was a good leak and I could feel it, but not hear it
Title: Re: How do you find all of the Air Leaks
Post by: turbojack on February 08, 2023, 05:58:41 pm
After being at FOT back in November they fixed all of my air leaks.  I have only heard the compressor run once and that was when I was opening a slide in the garage without running the engine. 

That was until last Saturday evening when I heard the compressor kick on around 9pm. and we had not done anything to use air.  After the compressor waking me a few times about every 2 hours, I got up and unplugged the fuse for the compressor.  Sunday Morning I ordered on Amazon the Amprobe ULD405.  The unit showed up at the house yesterday but I was not in the mood to hut down air leaks.  This after noon I decided to go and check out the ULD405.  I put the cone on tester and started in front pass bay.  It showed nothing.  I then opened door under driver and nothing. Held it under the front wheel front and back, nothing.  I go to the compartment with the compressor and did not even have to get close. I was about 2+ ft away from compressor and the tester was going nuts.  I then put the tube on the tester and found one of the push on air fitting connected to the compressor was the one that would make the unit go nuts.  It was quite in the building but I could not hear the air leaking.  I am going to get the wife out later and see if she could hear it.  I then went over the complete system with the cone and the only place it was going nuts was the compressor compartment.  I started playing with the tester and all I had to do was be around 3' from the compartment and the tester was going nuts.  I am totally impressed with the unit.  Testing this way was way easier then spraying kids bubbles.

The only down side to the tool, is it come in a big Amprobe Lunch bag tool kit.  I am going to look for something about 1/4 the size to keep it in.