Searching With Whisper - Found Leak But......

RandyA · November 19, 2016

I pulled the Volvo up on my home made solid ramps and attached a Charlie/Carl R134A high side fitting with an adapter to fit my shop air compressor. I did not really need the external charge air as my leak is very slow - but using it allowed me to check for leaks from the truck compressor to the dryer without engine noise interference.

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I went over every fitting, valve and air line. I found the leak, which made me happy. But, I am not happy with where the leak is. There is a solenoid valve body on the inside of the frame rail under the passenger seat. Air is leaking from the back of the solenoid body indicating that I will most likely end up replacing the solenoid pack. It can't be an inexpensive item! I'm not sure right now what the solenoid pack controls besides the air horn. I have previously disconnected that solenoid and replaced it with a single unit. Maybe I can get lucky and possibly eliminate the Volvo OEM solenoid pack if it controls some of the components I no longer have like the power divider. Looking at maybe one or two individual solenoids that are not Volvo OEM priced. Does anyone know right off the bat what the solenoid pack controls? One thing for sure - I never would have found this leak without the Whisper. There are no visible bubbles when spraying the thing with soapy water since the leak is on the backside.

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So, while I am using the Whisper I think of an accessory they sell for about $50 that attaches to the tip and turns the Whisper into a device like a Mechanic's Stethoscope with the solid metal tip. Shucks, there is nothing special about that thing I can see so I made my own. I had enough "stuff" on hand to make the tip. I listened to the different parts of the engine, alternator, compressor, to see if there were any knocking sounds or rough bearings. The good news is I didn't find anything abnormal.

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I greased it front to back - had to replace 3 fittings, checked and adjusted the rear brakes/slack adjusters, checked transmission and diff oil levels, front ball joints, steering linkage and hoses - again, all OK.

Now, to decide how I am going to fix the solenoid pack rear air leak. I guess first thing is to call Colonial Volvo Monday morning to get a price on the OEM Volvo part.

dblr · November 20, 2016

As I said to you at he FROG Rally this year, I never miss reading your posts and learn things from you. Not that I don't keep learning from others on here but for some reason yours stick out to me, now please stop so I don't keep spending money

adept99 · November 20, 2016

Randy;

Can you tell if what's leaking is o-ring based or a brass seat? As I'm sure you know, o-rings are usually easily replaced at your local friendly hydraulics store. The shop I worked at after I got out of the Navy had two full aisles of replacements in all sizes and materials. Might be worth a try.

Paul

RandyA · November 21, 2016

Paul, I did a search of the part number on Class 8 Truck Parts and discovered that the base for the solenoids is a separate item (look here). The base alone is $132.00 sans the possibility of needing new solenoids. Since the leak is on the backside of the base I believe it is most likely cracked or otherwise physically damaged. The catch 22 will be removing the solenoids from the base with the rusty screws in one piece. There indeed may be O rings between the solenoids and the base. Guess I will be crawling back under the beast and pulling the air lines and electrical connector off the base and solenoids and hoping the bolts holding it to the frame are not too rusty to take off. Maybe I will get lucky....... shucks, maybe it is just a small crack and some good old JB Weld will patch things up .

SuiteSuccess · November 21, 2016

So what does that gizmo do? Also got my ramps built, will send you some pics. Made mine to bolt together so I can keep them in my drom in case needed on the road.

RandyA · November 21, 2016

So what does that gizmo do? Also got my ramps built, will send you some pics. Made mine to bolt together so I can keep them in my drom in case needed on the road.

I spent some time immersed in the Volvo electrical schematics - an activity that I equate to having ingrown toenails removed. Anyway, what I found (or think I found) is the solenoid pack Y53a..... controls air lines for four different functions.

1. Air Horn (Previously rewired and re-plumbed to a new single solenoid)

2. Differential Lock (I don't have this feature so it is not needed)

3. Suspension Dump (I need this one)

4. 5th Wheel Slide (Don't need this one either)

So, it looks like the only function I need to retain from the solenoid block is the suspension dump. That function can be handled with a $12 external air solenoid and a "T" fitting off of a 1/4" air line (service to air horn?). I plug the 3/8" supply air line and abandon the rest of the solenoid block. No more air leak, and a lot less red money . (Green money you spend everyday for groceries, etc., orange money is for retirement and "red" money is for HDT, tools and 5'er stuff.)

PEIFamily · November 21, 2016

RandyA, on 19 Nov 2016 - 5:51 PM, said:RandyA, on 19 Nov 2016 - 5:51 PM, said:

I pulled the Volvo up on my home made solid ramps and attached a Charlie/Carl R134A high side fitting with an adapter to fit my shop air compressor. I did not really need the external charge air as my leak is very slow - but using it allowed me to check for leaks from the truck compressor to the dryer without engine noise interference.

I went over every fitting, valve and air line. I found the leak, which made me happy. But, I am not happy with where the leak is. There is a solenoid valve body on the inside of the frame rail under the passenger seat. Air is leaking from the back of the solenoid body indicating that I will most likely end up replacing the solenoid pack. It can't be an inexpensive item! I'm not sure right now what the solenoid pack controls besides the air horn. I have previously disconnected that solenoid and replaced it with a single unit. Maybe I can get lucky and possibly eliminate the Volvo OEM solenoid pack if it controls some of the components I no longer have like the power divider. Looking at maybe one or two individual solenoids that are not Volvo OEM priced. Does anyone know right off the bat what the solenoid pack controls? One thing for sure - I never would have found this leak without the Whisper. There are no visible bubbles when spraying the thing with soapy water since the leak is on the backside.

Class8truckparts has it for 132. It is the Solenoid mounting base plate. It may be as simple as a few orings that your connections bolt onto it at or the plate could be cracked maybe?

http://class8truckparts.com/volvo-truck-85104906-solenoid-mounting-base-kit.html And Amazon for 115. https://www.amazon.com/Volvo-Truck-85104906-Solenoid-Mounting/dp/B002GB5SNK/ref=cm_cr_arp_d_product_top?ie=UTF8

Jack Mayer · November 21, 2016

So, Randy, are you going to remove everything and clean that all up, then mount the single solenoid? I'm assuming yes....

I'd sure want to get rid of all the "junk". At our ages we are likely to forget what we did and try to figure it all out again in the future..... ....just trying to help, here

RandyA · November 21, 2016

So, Randy, are you going to remove everything and clean that all up, then mount the single solenoid? I'm assuming yes....

I'd sure want to get rid of all the "junk". At our ages we are likely to forget what we did and try to figure it all out again in the future..... ....just trying to help, here

Yes. If it is no longer used or needed I will remove it. The switches for the power divider and truck fifth wheel slide were removed several years ago and replaced with new switches for my designs. The ends of those air lines were plugged - they will now be removed. A new single solenoid for suspension air dump will remain - I ordered a solenoid last night and currently have plenty of fittings for the 1/4" NPT solenoid body and 6mm air lines on-hand. I will use the OEM dash switch to control the new solenoid.

Now Jack, I am guilty of often forgetting what I did - and age is of concern. Forgetting is one reason I did the rewire on all my add-ons several months back. I now label wires, take pictures, make drawings and write things down. But what scares me is if I become as addled minded as Carl what will I do? :lol: . (Just kidding Carl - I hope you can remember where you put your Hutch notes soon ).

Our Preacher recently commented to me, "Randy, at your age you should be thinking about the here-after." I told him, "I already do. When I go into a room I have to stop and ask myself what the heck is it that I'm here-after." :rolleyes:

SuiteSuccess · November 21, 2016

"But what scares me is if I become as addled as Carl what will I do? :lol: . (Just kidding Carl - I hope you can remember where you put your Hutch notebook )."

Now that's a low blow Randy, by the way, what were we talking about?

RandyA · November 21, 2016

Carl - I've had our boat in the garage for the past few days prepping it to go to Florida. I just spent close to two hours searching for the OEM wiring diagram for the trim-tilt circuit going to the dash gauge. I just had it yesterday and knew it had to be in the boat! Well, I finally found it. It had been neatly placed into a folder which was sitting on my table saw under a small shop towel. I honestly do not remember putting it in a folder and I have no idea why it was on the table saw or how the shop towel got on top - honest, not joking.

Brad & Jacolyn · November 22, 2016

Randy if it like mine one of those solenoids is for the fan clutch. That is the one I had to change out on mine. But my solenoid bank is under the truck in the middle. I believe the fan clutch is a green air line.

Plus if it is just the mounting plate $132 will buy a lot of JB Weld.

Brad

RandyA · November 24, 2016

Thanks Brad - I will be careful to determine if one of the solenoids is for the fan clutch. I did note when decoding the electrical schematic that it showed five solenoids while my truck has four. But, since I don't have a PTO I guess I got the short part. There are some other solenoids that are not part of the problem block. I'll look at the schematic again to see if I can determine what they control. They did not label the solenoids with a name - only a wire number that you must find on yet another page. I should be able to trace the air line for the fan clutch back to it's solenoid - wherever it is.

SuiteSuccess · November 24, 2016

Randy,

My fan clutch solenoid is on drivers side frame rail towards the front almost to the radiator. I have the D12 also.

BTW are you putting a jack stand under your truck when you have it up on the boards? I have a set of 12 ton (6/side) but not sure if that is adequate.

Brad & Jacolyn · November 24, 2016

Randy,

I just looked in my maintenance log and found this description of the colored air lines on the manifold. Scrape to paint on the lines so you can see the color.

Green = fan clutch

Red = Air horn

Black = Suspension dump

Yellow = 5th wheel slide

Gray = Inter axle diff. lock

Don't remember where I got it or who sent it but this matches my truck.

Brad

RandyA · November 24, 2016

Thanks Brad, that will be useful. In fact, it is now in my air line manual ('cause I just put it there!)

Carl, no way the solid ramps are going to collapse. Jack stands just get in the way - and I am extremely safety conscious. IMHO, (besides solid ramps) the second most important thing to do when the front wheels are on ramps is to chock the rear wheels - both forward and reverse on both sides. Third most important thing is to wear full safety glasses or goggles so stuff doesn't fall in your eyes. Fourth is never work alone - someone else needs to be there watching, preferably with a cell phone (and to hand you tools).