Disc brake dually

[LCAM-01XA]

Oh yeah, the hydro is the way to go for improved braking performance. All I was saying is it's not always needed (I've driven quite a few trucks that stopped just fine on vacuum), and there is at least one area the vacuum has the upper hand over the hydro.

FWIW to me the Ford hydro swap how we typically do it here kinda sucks. Not in stopping power, it's got plenty of that, but the pedal just doesn't feel quite right. Now, mind you, I'm comparing the monster master in a drum-braked Ford to the full-factory GM setup in a comparable 1-ton truck of similar vintage, so a bit of apples to oranges, but still, to me the hydro-swap without rear discs leaves something to be desired as opposed to something that was engineered that way to begin with. I've been playing with these things for years now, trying different combinations of masters and pedals trying to get it "just right", and I think the best results yet came from a truck that retained all of its factory brake parts except for the booster - that one just got the hydroboost mounting plate modified to drop the hydro down to where it lines up exactly like the vacuum booster did, holy cow did that thing stop like a race car yet still had pedal feel very much like a new truck. I just wish the pedal swap was easier in the '91-down trucks, not looking forward to that job again...

 

[towcat]

hydro will never feel like vac brakes. I am very familiar with GM hydro both in truck and turbo Regal form. Even BMW hydro is a different animal. I had a OEM setup in a gray market M6. Rather than make something mimic a feel, I'd rather have it work right. Every one of my ford hydros have a different "feel" (some less touchy than others), but the bottom line, imho there's no two vehicles will feel the same

 

[LCAM-01XA]

Oh I know the hydro and vacuum feel different, I was comparing a converted Ford hydro to a factory GM hydro. Tho I gotta say one of the best in both performance and pedal feel has been the factory F-Superduty setup (in a F-Superduty truck I mean), which is hardly surprisng since that's what the system was engineered to work with. And since I always hated drums, the solution to this whole conundrum seemed easy enough - keep the hydro and big master in their factory form, and drop in a factory Ford axle with large disc Still need 3.54 gears and a whatever limited slip comes along for reasonably cheap tho, then it's game on!

 

[riotwarrior]

From the early 80s F700 or what ever it was I drove..hiab deck truck diesel 2sp and elecric over hydro...I hqve loved the hydros.

They kick the tail off the donkey.

Any vehicle maintained properly could suffer catastrophic failure of any or multiple systems...faith keeps me going they wont fail...faith my brakes work allows me to drive comfortably.

Tonight for chitznggilze I on a back road...hard wired my two large round lights to see....wow..they are getting switches and relays asap....I drive really slow at night to not outdrive my lights...but I doubt I can out drive my brakes...

A Brian @IdIot cut me off tonight in town and I was able to stop RTFN not even close to them...that can opener bumper would hqve destroyed that micro pos cqr

just saying...love hydro...

 

[LCAM-01XA]

That F700 hydro is the one I wish we got in the light trucks, it's got the electric backup pump. But with a 2" or larger master cylinder, yeah, need a tander rear with discs all around to make use of that monster

 

[The Warden]

I was comparing a converted Ford hydro to a factory GM hydro. Tho I gotta say one of the best in both performance and pedal feel has been the factory F-Superduty setup (in a F-Superduty truck I mean), which is hardly surprisng since that's what the system was engineered to work with.

Having put a number of miles on a Chevy C5500 bus, I have to say that I'm underwhelmed by GM's hydroboost system that that bus is equipped with, although maybe the system's better on a smaller pickup? I've also had the pleasure of driving an F-350 CC DRW with a fully done hydroboost conversion (proper pedal assembly, F-450 master cylinder) as well as three different F-550 buses with factory hydroboost, and they work quite well

 

[fsmyth]

Just to toss this in - the GMC series 60 (unloaded, it's a chassis only) feels pretty
much like my 2500 series Dodge pickup. Either one feels good. The little pickup
has stopped some stuff that it really didn't want to move in the first place.
Neither one can stop as good as the Chev 70 series with air - but it has SERIOUSLY
bigger drums. More like the Mack. If it will move it, it will stop it.
And I need that. Most of the crap I have to move either 1) the trailer brakes are
non-existent, or 2) the hookup is wrong.
As an aside, the GMC and the Dodge (front only) have discs. The rest are drum brakes.

 

[typ4]

Tim, chevy brakes newer than early 80 ish, suck. we have a 2000 k3500 cc , same pads as a 1500, big wide shoes on rear but still these stupid little pads and single piston calipers up front. Hydro but still sucks,
Now, I have a gm hydro, no real difference functionally from the ford, on the 88 dually and it is like super touchy brakes, yay ford wheel ends.

 

[oztinker47]

It seems to me the reason the ford vacuum assist is so weak is the small diameter booster,
It's tiny compared to the booster on my '95 GMC K1500 . More diaphragm surface area means more force from the same pressure differential, which translates into less leg force needed to stop.
As for the hydroboost popping a line, that can be prevented in the most part by inspecting the lines regularly. They usually start weeping oil around the crimp before they blow.

Sent from my XT1028 using Tapatalk

 

[riotwarrior]

Did failure test today...

While driving down a long steep hill in neutral I turned off engine.

It was some fun and effort however I managed to keep truck steered and stopped it.

Pedal effort was high but managable

Should try it guys

 

[fsmyth]

hydro will never feel like vac brakes. I am very familiar with GM hydro both in truck and turbo Regal form. Even BMW hydro is a different animal. I had a OEM setup in a gray market M6. Rather than make something mimic a feel, I'd rather have it work right. Every one of my ford hydros have a different "feel" (some less touchy than others), but the bottom line, imho there's no two vehicles will feel the same

When I have as many old trucks, RUNNING, as you, I will feel more confidant about posting the differences
How good a truck is the '90 F450? Been looking around for one similar, but haven't found anything yet.
Does the N/A pull it well enough to work it?

 

[towcat]

When I have as many old trucks, RUNNING, as you, I will feel more confidant about posting the differences
How good a truck is the '90 F450? Been looking around for one similar, but haven't found anything yet.
Does the N/A pull it well enough to work it?

for years I told my guys who drive them....."you won't win any races, but you will finish your day". F450's are geared where you will get 15K/lbs moving at a reasonable speed, but you will top out at 85mph and when you see a 6% grade, you will slow down. but with the hydro, you will bring the whole mess to a stop without fear. that was what sold me on Ford F450's back in 1993. my previous truck was a '74 GMC 1ton with a holmes 440 sling. Stopping was real dicey when I had a heavy load on the sling. with the F450 carrier, no hesitation whatsoever. hope this helps.

 

[FORDF250HDXLT]

How good a truck is the '90 F450? Been looking around for one similar, but haven't found anything yet.

keep your eyes on this thread then.
http://www.oilburners.net/forums/showthread.php?75477-Diesel-F-Super-Duty-F450-s!

 

[brokeasajoke]

Vacuum sucks! Hydro is awesome. Replaced everything (calipers, pads, rubber hoses, shoes) including booster on my 88 DRW. Took it off and sent it packing. These should have come OE with hydroboost. The hydro swap does to the brakes what a turbo kit does for the motor. Daylight and dark.

 

[fsmyth]

for years I told my guys who drive them....."you won't win any races, but you will finish your day". F450's are geared where you will get 15K/lbs moving at a reasonable speed, but you will top out at 85mph and when you see a 6% grade, you will slow down. but with the hydro, you will bring the whole mess to a stop without fear. that was what sold me on Ford F450's back in 1993. my previous truck was a '74 GMC 1ton with a holmes 440 sling. Stopping was real dicey when I had a heavy load on the sling. with the F450 carrier, no hesitation whatsoever. hope this helps.

Sorta what I thought. Must be 5:13 or 4:21. Never had one, but that may change. 85 mph is plenty fast for me.
Sounds like it needs a New Process or Saginaw with overdrive. Or a brownie. Just curious how well it got it moving.
Will probably stick with big-block gassers for medium duty. Seems to work out better, except for winching.