Dsl_Dog_Treat
I lost my face to the jaws of a poodle
Yup, a properly functioning hydroboost system WILL find the weakest line.
In a hurry!
In a hurry!
hydroboost
- Thread starter Mat J
- Start date
david85
Full Access Member
900-2000 psi? Now thats an upgrade!!!!
Finally I understand why it makes such a big difference. Dang......
MLSC; Yeah, we can certainly agree on that. Do not disable the ABS unless you are planning on putting a proportioning valve in to compensate and you damn well better know what you are doing when setting it up. In some cases, a HD wielding rig or steel flatbed might already compensate enough however, so its a case by case basis.
As I said with my dad's truck, it actually has 4 wheel ABS already and still is nothing but trouble whenever things get hairy. It not surprising to see ABS equipped vehicles getting poor stopping power when its not activated simply because the car/truck wasn't intended to function that way.
Its true to an extent what you are saying about wheels locking and longer stopping distance, but there are cases when being able to lock the wheels is helpful. Soft terrain like gravel is one situation where ABS will usually result in longer braking distances according to what I've read.
I just don't like having that decision take out of my hands. But I've been driving my truck for long enough that I know how much force will cause lockup, and in essence, I am the ABS system.
Now thats an upgrade!!!!Finally I understand why it makes such a big difference. Dang......
MLSC; Yeah, we can certainly agree on that. Do not disable the ABS unless you are planning on putting a proportioning valve in to compensate and you damn well better know what you are doing when setting it up. In some cases, a HD wielding rig or steel flatbed might already compensate enough however, so its a case by case basis.
As I said with my dad's truck, it actually has 4 wheel ABS already and still is nothing but trouble whenever things get hairy. It not surprising to see ABS equipped vehicles getting poor stopping power when its not activated simply because the car/truck wasn't intended to function that way.
Its true to an extent what you are saying about wheels locking and longer stopping distance, but there are cases when being able to lock the wheels is helpful. Soft terrain like gravel is one situation where ABS will usually result in longer braking distances according to what I've read.
I just don't like having that decision take out of my hands. But I've been driving my truck for long enough that I know how much force will cause lockup, and in essence, I am the ABS system.
LCAM-01XA
Full Access Member
David, good point on the welding rigs and the heavy flat beds, those can indeed make up for the high line pressure to the rear brakes - with those I think an adjustable proportioning valve will be a good thing to install, instead of a factory valve, then it can be dialed in as needed and liked by the driver. I actually had one of these in my Chev, being a shortbed stepside of only 3700 lbs with the 1-ton hydroboost and master and the larger 1-ton rear wheel cylinders that truck was a combination very far from any factory setup, so I put in the manual valve and played with it till I liked the results - braking power was quite impressive, yet it was VERY hard to get it to lock up and start sliding.
And I completely agree with the ABS performance on gravel and loose dirt. That's why most new vehicles have the ABS and TCS (and often the VSES) integrated together, and in certain occasions the results are pretty darn wicked - the big GM hybrid SUVs for instance, these can have the electronics systems tuned up quite aggressively, to the point where one of our test drivers just refused to drive them - in his words the darn thing was so good at doing its job, it was like it was reading his mind and counteracting the moment he tried something, and therefore it was a total waste of testing time to go mess with them on the skids pads and splits.
And I completely agree with the ABS performance on gravel and loose dirt. That's why most new vehicles have the ABS and TCS (and often the VSES) integrated together, and in certain occasions the results are pretty darn wicked - the big GM hybrid SUVs for instance, these can have the electronics systems tuned up quite aggressively, to the point where one of our test drivers just refused to drive them - in his words the darn thing was so good at doing its job, it was like it was reading his mind and counteracting the moment he tried something, and therefore it was a total waste of testing time to go mess with them on the skids pads and splits.
david85
Full Access Member
Before the RABS, they have some sort of load sensor on the rear axle of F250s. My truck has this. I'm not sure how exactly it works but it seems to function like a dynamic proportioning valve that adjusts based on how much the rear of the truck squats down from trailer or cargo weight. Some guys are able to bypass this.
Seems to work very well because I've never had my front tires lock up while backing a trailer down a steel incline on gravel. My F150 always needs a little pressure on the E brake to keep things in control. I still have to replace the leaf stack on the other side of my truck. The new springs seem to raise everything in the rear by at least an inch. Hope it won't throw anything out of wack at the new ride height.
I am seriously thinking of a hydroboost upgrade though. Probably only a matter of time before I go through with it even if I don't need it right now. If I do, I might take the time to replace all the steel lines with stainless steel. Lots of time on salted freeways take their toll on regular brake lines. Next to the midship fuel tank or at the rear axle itself, they always rust out. 2000 psi of pressure, still can't get over that.
Seems to work very well because I've never had my front tires lock up while backing a trailer down a steel incline on gravel. My F150 always needs a little pressure on the E brake to keep things in control. I still have to replace the leaf stack on the other side of my truck. The new springs seem to raise everything in the rear by at least an inch. Hope it won't throw anything out of wack at the new ride height.
I am seriously thinking of a hydroboost upgrade though. Probably only a matter of time before I go through with it even if I don't need it right now. If I do, I might take the time to replace all the steel lines with stainless steel. Lots of time on salted freeways take their toll on regular brake lines. Next to the midship fuel tank or at the rear axle itself, they always rust out. 2000 psi of pressure, still can't get over that.
LCAM-01XA
Full Access Member
Yeps, those load-depending proportioning valves do work great, till they corrode, then they suck. My buddy's '86 has one, but it ain't functional as the rear axle of the truck is a light-duty Sterling from something that has RABS (has a VSS on it), and therefore it has no provisions for attaching the valve actuating arm's linkage. Truck seems to stop just fine without it tho, but then again he only uses it to drive around town and never tows with it.
Mat J
Way down south
thanks for all the good info guys
