HydraMaster 4.8

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Feb 23, 2012
6
1
0
ca
Real Name
Dan Staggs
Business Location
United States
#1
I have a 03 Chey Express 6.0 with a HM 4.8 w/Salsa. I only heats up to about 160 on regular and then when I turn it to salsa it drops and stays to about 145 even if I switch back to regular heat. I have run vinegar through it twice & all fiber rinse but no changes. The temp gauge on the van dash it at 210. There isn't any build up inside of the normal/salsa valve. HM said it could be the van's water pump but the vans temp is normal. The only thing about the water pump is there is a leak in the water pump when it's hot and you shut it off it does leak a little coolant but just a little bit. Could the water pump still be the problem or could you suggest any thing else ?

Thanks Dan
 

AvidCare

Active Member
Sep 25, 2011
749
75
28
Kansas
Real Name
Patrick McAnulla
Business Location
United States
#2
You more than likely have an Air Lock in the coolant line that is not letting the coolant run through normally. It is crutial that their is no leaks in the system for the coolant to flow properly. My suggestion is to pop the hood make sure you have plenty coolant in the reserve. Then behind the passanger seat you will see the coolant lines go to the heat exchanger. There will be a petcock valve with a clear tube that is there to remove the air. You will have to get the engine hot. Start bleeding off coolant, it will take a while to get all the air out. just have someone with you to switch off containers and put excess coolant back into the coolant reservior. It will make it much easier to do this if you pull the passanger seat out. It is not hard and makes it very easy to do your maintenance work. Make sure that you run your heater in the van while doing this so the air will not build up in the heater core.
When air is in the line it actually restricts the flow of the coolant like a damm.
When it is time to descale the heat exchangers I always took a 5 gal. bucket. with 2 long heater hoses, and a pond pump. Filled the bucket with the White Vinigar attached the hoses directly to the heat exchanger and than back to the bucket. The pond pump should have a nice foam filter on it. I would plug it in and let it circulate all weekend and then Poof she was one Hot Seniorita!!!!!! This will mildly clean your HE. Your machine pump and van isn't doing all the work. Pond pumps run anyware from 40 to 90 bucks. If you do this once a month you should never have to run de-scaler again.
I hope this episode of Kansas Hick Garage was informative. Oh and if you see Dorthy tell her not to come home, we don't miss her.. LOL
 

AvidCare

Active Member
Sep 25, 2011
749
75
28
Kansas
Real Name
Patrick McAnulla
Business Location
United States
#3
Staggs,


Did you get a chance to check this out.
 
Feb 23, 2012
6
1
0
ca
Real Name
Dan Staggs
Business Location
United States
#4
I'm sorry I haven't replied sooner, if I had a air lock wouldn't the van over heat when you dont bleed the air out of your cooling system the engine overheats. The hydramaster dealer told me to use a jumper hose between the pressure output & the freshwater in quick connects that would do the same. There was no petcock valve for the engine coolant to heat exchanger hoses. No luck so far still wont get above about 145 degrees.
 

Jim Martin

Well-Known Member
Jun 5, 2008
2,656
260
83
Tucson Arizona
#5
not knowing where it is leaking....but..if it is leaking at the bottom then more then likely the water pump is going out....there is a weep hole at the bottom of the pump....when the pumps start to go out then that is the first indication that you had better get it replaced before it is to late...

if the pump is going out then it would affect the circulation to the van and the machine...

you may also want to try to burp the entire system....but to be honest..I would lean more towards the pump....
 
Apr 4, 2007
4,373
11
0
Mn
Real Name
Jesus
Business Location
United States
#6
Jim is right when it starts to drip then it's the water pump.
 
Feb 23, 2012
6
1
0
ca
Real Name
Dan Staggs
Business Location
United States
#7
I know that the water pump has a slight leak where the backing plate bolts to the pump it self. After it's hot and turned off you can see a little trickle of engine coolant and I have gotten my mirror up there and can see it's leaking the bottom bolts. I'll try changing the pump and see what that does.

Thanks Dan
 
Feb 23, 2012
6
1
0
ca
Real Name
Dan Staggs
Business Location
United States
#8
On my CDS 4.8 model there is a plastic premix tank, In side one of the hoses going to it is a screen that was plugged up. Now when running on the Salsa setting I get temps about 190 but it does seem to float up or down about 10 degrees. Still on normal heat setting the temp stays around 140. I checked the temp in the premix tank after running the truck on a job for two hours and it was barley luke warm.

Dan
 
Feb 23, 2012
6
1
0
ca
Real Name
Dan Staggs
Business Location
United States
#9
Thanks to everyone I appreciate all your help but I'm still having problems with fresh water not getting hotter that about 170. I found the owners manual on line and saw where the petcock was supposed to be but mine didn't have it and didn't have the hole in the fitting for it. I cleaned the screen in the line going to the salsa box between the seats and that help just for a little while but went right back to where I was at. I put a new Bosch water pump, thermostat and lower hose but still no change. I have taken the salsa heat exchanger out and cleaned it I have connected a garden hose to all 4 fittings of engine coolant side the main heat exchanger to make sure there was no restrictions and have run vinegar and all fiber rinse through the fresh water side. Anyone have any other ideas I would appreciate it before I have to have the local Hydramaster dealer look at it ?

Thanks Dan
 
Apr 25, 2017
1
0
1
Real Name
Keith young
#10
I hope some one can help me out on this equipment hydro master 4.7 CDS
With a 2002 Chevy 2002 Econoline
Question
Exactly where would the the (2)hose from the hydro master 4.7 connect to on a Chevy van..

Question:
Do I remove the thermostats hose and put the 4.7 in the loop
 
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