iRV2 Forums

iRV2 Forums (https://www.irv2.com/forums/)
-   Ford Motorhome Chassis Forum (https://www.irv2.com/forums/f23/)
-   -   Hydro-Max Brake Pump/Motor Info Please! (https://www.irv2.com/forums/f23/hydro-max-brake-pump-motor-info-please-268071.html)

wihakowi 10-25-2015 09:40 AM

Hydro-Max Brake Pump/Motor Info Please!
 
Can someone describe to me what the proper operation of the Hydro-Max Pump/Motor is? By that, I mean when should it be running? Key on? Key off? Only when brake pedal is depressed? When should it not be running? What should it sound like? How much of drain on the battery should it be?

The reasons I ask: Looking at a 2008 FW Terra 34G on a F53 22k chassis.
~ The Hydro-Max pump/motor comes on as soon as the key is turned to the on position. It stays on until the engine is started - no matter how long a period that is. It may even be running while engine is running (I hear a vibration noise but have not checked directly to see if it is the pump/motor). I have read varying opinions as to what proper operation is.
~ It makes a very loud, almost grinding noise - sort of like a starter motor where the teeth are bad. Very annoying and never shutting off just doesn't seem correct.
~ It is on with NO pressure on the brake pedal.
~ The battery control center does not seem to be charging the House battery when the MH is running and during a long drive like it should be. I'm thinking that perhaps a constantly running Hydro-Max motor is "sucking up" enough juice that the BCC never senses that it can divert power to charge up the House battery.

Any thoughts that will help me understand whether this system is working incorrectly and may even be leading to other issues associated with a less than charged House battery are appreciated.

Thanks

ga traveler 10-25-2015 10:33 AM

The motor provides power steering and power brakes if the engine dies while you are driving. That way you can steer and stop the motorhome if the engine should go dead while driving. It will run anytime the switch is on and the engine is not running. It IS noisy.

ga traveler 10-25-2015 10:41 AM

On the battery charging issue,just take a volt meter and read the batteries while the engine is running. The batteries will read about 12.6 to 12.7 if not charging and 13 to 14 volts if receiving a charge.

Hikerdogs 10-25-2015 02:47 PM

In addition to what ga traveler has mentioned the pump will also run if the brake pedal is depressed with the engine off. The newer models also do a self check and run for about a second when the motorhome reaches 25 mph.

If you think the pump is running while the engine is running open the hood and feel the pump. It's just below and to the rear of the master cylinder.

Here's a link to the 2014 F53 brochure.

https://www.fleet.ford.com/resources/...2014_LoRes.pdf.

The master cylinder and reservoir are almost directly in front of the steering column. The Hydro Max motor is the silver thing just below the master cylinder.

The Hydromax motor should not be running when the engine is running. There is a pressure sensor in the power steering system that is supposed to be open when the power steering pump is supplying the proper amount of pressure to run the steering and brake systems. If the motor continues to run while the engine is running either the sensor has failed or the power steering pump is not supplying sufficient pressure.


wihakowi 10-25-2015 04:42 PM

Thanks for the great replies.
Can someone describe the sound (noise) a normally functioning pump makes with key ON, no pressure on brakes. If the one I'm looking at is normal, I wonder how people can stand to be in the MH, much less up front! Thanks

ga traveler 10-25-2015 11:28 PM

Quote:

Originally Posted by wihakowi (Post 2798708)
Thanks for the great replies.
Can someone describe the sound (noise) a normally functioning pump makes with key ON, no pressure on brakes. If the one I'm looking at is normal, I wonder how people can stand to be in the MH, much less up front! Thanks

as I said in my previous post, it is noisy. It is not a problem because you will not be driving with the engine off.LOL The motor is not running after you start the engine because you would be ale to hear it over the noise of the engine.

grtharris 10-27-2015 10:03 AM

Mine will only come on if the brake pedal is pushed, key on or off and the engine not running.

wihakowi 10-28-2015 06:25 AM

Quote:

Originally Posted by grtharris (Post 2801021)
Mine will only come on if the brake pedal is pushed, key on or off and the engine not running.

Thanks (to all). The above is how I would think the system should work. Why would anyone be expected to listen to that grinding buzzing noise while setting the GPS or pulling codes or listening to the radio?

The other thing I tend to do after driving in cooler weather is to run the engine heat into the cab for a few minutes after I land - to "use up" all that heat in the system. What a pain to have to listen to extra unnecessary noise just to try to be efficient.
Am I missing something?

grtharris 10-28-2015 08:59 AM

1 Attachment(s)
wihakowi, There are two switches ( the Hydro-Max Flow Switch and the Brake Pedal Position Switch) and two relays( the Hydro-Max Brake Signal Isolating Relay and the Hydro-Max Relay)
Attached is the drawing for 2014 F53 I don't think the brake system has change much.


All times are GMT -6. The time now is 09:07 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.