Hi, everyone! This is my first post here, but I've followed the forum for close to a year now. I finally have a truck of my own so I now have a reason to post. I have a 1995 Mitsubishi Minicab 4WD, and it is probably my favorite vehicle to drive now - and this isn't my first import, either. However, one issue prevents me from making my truck a semi-daily: braking fishtail. It's happened a few times at a variety of speeds, ranging from 15 MILES per hour to 50mph, but when I brake pretty hard, the rear end slips. Like crazy. I ended up rotated 90 degrees on the street last weekend when a traffic light changed far too quickly. I figured this was due to all the weight in the front of the truck, but I've never heard about this issue from anybody else. Just thought I'd ask here before I toss a few 50lb bags of sand in the rear of the bed to see if that helps, either diagnosing a potential issue or offering potential fixes. The truck had relatively high mileage (90k~ miles) but it came with a lot of service records, and the brakes were redone pretty recently. They look fine, as well. Thanks for any help or insight! Very happy to be an official member now!
Okei, Welcome! Anytime I've heard of these issues involving any vehicle, naturally weight, the inertial energy distributed fore ward, and the composition of the vehicle itself, being lift vs dramatically lower front end! Most importantly with all these issues playing Vital importance, the first thing that I would look at is my brake set up! If your front brakes are working extremely well, and your rear brakes aren't, there could be an issue there, helping to cause your fishtailing problems! It does help that you are not really green to the mini truck experience. In order to fishtail, tire condition enters the equation also. Adding sand bags to the rear has always helped, but I would seriously evaluate this further, and I really think that you'll figure it out without the sand bags, and not reducing your fuel mileage! I would like to see several pics of your unit, from the side, showing vehicle leveling, suspension, lift info, tire tread, showing the tire wear. In your Signature you show that you have more than one vehicle, that's great, but I'm assuming their everyday drivers, because you don't state that in your profile. I'm sure you've noticed, that these little mini trucks are used in all sorts of ways. Hopefully, collectively we can help you figure this out! There's a great group on this Forum, that are willing to weigh in. It could very well be a combination of a few things. Good Luck! Limestone
Check the front brakes. The rear end is locking up and then sliding past the front. In theory the front and rear should have equal braking. But it is hard to get them synchronized on trucks. Because the differences in loading meaning the when loaded you need more pressure to the rear, and when unloaded you need a lot less pressure. There may be a secondary proportioning, aka squat, valve, which is hooked by a link to the rear axle, so as the truck squats under load, it opens and lets more pressure go to the rear. The Toyota pickups, first got the valve system in 79, the ones before that, including the 77 I had didn’t have the rear adjusting valve, and I was the only person who could drive it, without it fishtailing. I spent several late nights driving it around parking lots late at night after everything was closed learning to control the skid by reflex. After a few nights I had it down, but other people couldn’t drive the truck..
Hey all! Thank you so much for your insight and inquiries, and I'm sorry for not responding WAY sooner. I got real busy and totally forgot about my question. I've looked for a secondary proportioning valve but couldn't find anything, and the brakes look great, front and rear. I went through the service records included with the truck (it was single-owner) and there hasn't been any braking or suspension issues noted, and maintenance was very well kept up. I'm not going to worry about it for a few reasons. This truck is more of an off-road toy, I'm very partial to the Sambars for street driving so that will be a future commuter. 250 pounds of sandbags in the back totally fixed the issue, and it feels just great still, no noticeable hit to acceleration or fuel economy. I still average about 35mpg with foot to the floor, and like I said it's meant for off roading so that's not a big deal to me. Once again, thank you all for your help! I look forward to interacting more on this site!
If the issue continues I guess I'd do some further disassembly, and see the condition of the pads, rotors, shoes and drums. Calipers and wheel cylinders too... there may be something amiss... I've never had a problem with lock-ups, certainly not to that extent. Almost went nose-over in my old Mitsu once though, ya those brakes worked real good...
