Vacuum check valve cause of my front hub grinding issue.

Discussion in 'Raptor Maintenance' started by rabtech, Jan 9, 2019.

  1. rabtech

    rabtech New Member

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    Nov 20, 2018
    I have had my Raptor since Dec 31 2016. I have 48000 miles on it and like many here I run the ^%$^%#$% out of it. I am like most. I only post when I have a problem. However I may have a fix for some that have the front hub grinding issue.

    At 10,000 miles I was on the interstate and the front hubs started trying to lock in at 90mph. For those that have had this happen its quite a loud grinding noise......I was 600 miles from home and pulling a race car trailer. I eased off the gas and let it lock in. First the left hub and then the right hub. The steering wheel jerked as they locked in. At this point I wasn't sure what was happening but as I drove I could ease off the gas and the hubs would lock and the rattling would stop. I finally reached up on the dash and flipped it to 4A and they locked in and I drove home that way. The next day I went to Autozone and grabbed the electric 4wd vacuum solenoid. Well it didn't fix the issue. I am a good way away from a ford dealer and I need to be on the road almost every day so I try to handle stuff myself if its not that big of an expense. Since the solenoid didn't fix it I knew I could just let the hubs lock in and put it back in 2wd. I just plugged off the vacuum line going to the hubs and let the front axels just turn till I had time to leave my truck at the dealer. 10,000 miles later I let the Ford place have it for a few days and they said both hubs needed changing. When I picked it up it was perfect. At least it was until I put 5000 more miles on it. ..... It started doing the same thing again. So I plugged the vacuum line and let the hubs lock in and drove it tlll last week. It has 48000 miles on it now. SO most of its life i have been turning the front axels.

    I know some of y'all are screaming at the computer screen by now that have had this issue. Your probably asking why I didn't check the inline vacuum check valve. And the answer is ,,,, I did... I checked it the first time it happened while I was replacing the solenoid. However when I checked it I used the method that many people do. I put it in my mouth and tried to blow air through it and then suck air through it. And it worked. It wouldn't let me blow through it from one side and it would from the other. (It was ok) At least I thought it was.

    Well last week I had had enough of it and was going to carry it to ford for the second time. But I wanted to look under the hood one more time. For some reason I just did not believe that check valve was working. So I pulled it back off and grabbed my MightyVac and pumped it up. And it initially looked like it was holding a vacuum then it started slowly leaking off. I ran to AutoZone and grabbed another check valve for $4.00 and stuck it in and guess what..... My truck is fixed.

    I guess the moral of this is if your having this hub grinding issue change the vacuum check valve. And don't trust it by blowing through it with your mouth. I am betting that was all that was wrong the first time. I didn't notice if they change it as well as the hubs.

    I love my Raptor.... I had a 2013 Raptor and this is just a beast compared to it. And the only other issue I have had with it is a constant battery drain. It started this about 2 months ago. If I drive it every day you never notice it. However if I leave it for more than 3 days it will not start. I have unhooked the positive cable from the battery and put a test lite on the positive battery cable and the other end on the positive battery terminal. The test light comes on showing the drain. I have pulled EVERY fuse under the hood and the test light never goes out. I haven't pulled any of the in cab fuses yet to check to see if those circuits were the cause. I may do that this weekend.

    Anyone else had this battery draining issue?

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