1990 Suburban project
- Thread starter hidesertwheelin
- Start date
ntsqd
Heretic Car Camper
The theoretical ideal RPV for discs is 2 lbs. and is supposed to be only needed when the m/c is below the level of the calipers. The reason being that the RPV keeps the brake fluid from backing up into the m/c's reservoir and overflowing. I have heard of and have seen systems where adding one, when the m/c is above the calipers, has resulted in reduced pedal stroke.
Drums need a 10 lbs. RPV to keep the shoe retraction springs from doing too good of a job. I've read of some guys using the 10 lbs RPV on a disc system. My best guess is that they ended up with some of the late model high retraction front calipers somewhere in their brakes and have an otherwise 'normal' system. My '91 has these calipers & there is nothing external to indicate their difference.
Normally putting a 10 lbs. RPV on a normal disc system will result in excessive pad drag. I would expect that it would also do this with the high retraction calipers too, but that does not appear to be the case.
Grim, I'll meet you in Amarillo. :sombrero:
Drums need a 10 lbs. RPV to keep the shoe retraction springs from doing too good of a job. I've read of some guys using the 10 lbs RPV on a disc system. My best guess is that they ended up with some of the late model high retraction front calipers somewhere in their brakes and have an otherwise 'normal' system. My '91 has these calipers & there is nothing external to indicate their difference.
Normally putting a 10 lbs. RPV on a normal disc system will result in excessive pad drag. I would expect that it would also do this with the high retraction calipers too, but that does not appear to be the case.
Grim, I'll meet you in Amarillo. :sombrero:
chasespeed
Explorer
Get a master cylinder that matches the bore size for your rear discs, AND, the hydraboost is a great thing... EXCEPT, that if you stall, there is no reserve like your vacuum set-up....so, pushing those brakes can become an issue w/o engine power.
That said, I wouldnt trade my hydraboost for anything(I am sure Dodge calls it something different but... whatever)....
Chase
That said, I wouldnt trade my hydraboost for anything(I am sure Dodge calls it something different but... whatever)....
Chase
ntsqd
Heretic Car Camper
Front brakes do most of the work. Match the m/c bore to the front brakes, then match the rear calipers to the m/c bore, then work on fine tuning the brake bias with a P-Valve if necessary.
That long shinny cylinder on the booster unit itself is an accumulator. You should get at least one full stop out of it with a dead engine. More if you never fully release the brakes.
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chasespeed
Explorer
First, I should have read the thread, but, I was under the impression that he did a 1 ton brake swap with the 14b... which would mean, all he needs its the master that would work with the rear discs... but, after reading the whole thread, I see that isnt the case.....
AS far as the accumulator, that may be so... but, never did have one that worked.... I have always had to STAND on the pedal w/o the engine running...
I will probably flush the system and add a cooler when I plumb my winch...
Chase
AS far as the accumulator, that may be so... but, never did have one that worked.... I have always had to STAND on the pedal w/o the engine running...
I will probably flush the system and add a cooler when I plumb my winch...
Chase
ntsqd
Heretic Car Camper
Ah, now I see why you said that and I agree, you are correct now that I understand the perspective that it was said from.
Sounds like your accumulator has/had a high bleed rate and was defective. Unfortunately that isn't uncommon enough. The Early Bronco guys as a group were among the first that I know of to start adapting H-B's to something that didn't originally come with them. Most of the units are JY sourced, and once in a while a guy will get one that does that.
Heads-up on mounting a MM winch in a system with an HB unit; the civilian MM control valve favors the brakes. You can not stand on the brake and run the winch. A friend learned this the hard way with his PSD. It could be that the PS pump on that unit just couldn't keep up with both demands, but I would think that if this were the case that it would be momentary as the HB demand on the PS system should be momentary. Sadly that wasn't the case with his.
I say "civilian control valve" because I've no idea if the military control valve has the same behavior designed into it or not.
Sounds like your accumulator has/had a high bleed rate and was defective. Unfortunately that isn't uncommon enough. The Early Bronco guys as a group were among the first that I know of to start adapting H-B's to something that didn't originally come with them. Most of the units are JY sourced, and once in a while a guy will get one that does that.
Heads-up on mounting a MM winch in a system with an HB unit; the civilian MM control valve favors the brakes. You can not stand on the brake and run the winch. A friend learned this the hard way with his PSD. It could be that the PS pump on that unit just couldn't keep up with both demands, but I would think that if this were the case that it would be momentary as the HB demand on the PS system should be momentary. Sadly that wasn't the case with his.
I say "civilian control valve" because I've no idea if the military control valve has the same behavior designed into it or not.
chasespeed
Explorer
Mine is a MILSPEC version. It is plumbed between the H/B and steering box, leaving power to the brakes( a MILREQ).......
And my H/b only has 111k on it.....
Chase
And my H/b only has 111k on it.....
Chase
DavidG
Adventurer
Where were you a few years back! I searched for over a year before I bought my '91, owned it for around 6 years before selling it.
Barn Doors...check
4L80E...check
8600 GVW...check
Stock injected 350, bunk in the back and tons of storage. Front and Rear A/C, rollup windows, vinyl interior, small lift with 255/85 BFGs on stock steels, IIRC it had a 44 gallon tank....and it was ExPo white
Man, I loved that rig. The new owner still drives it
Great platform to build on!
hidesertwheelin
Explorer
Well it's been a while. Life got in the way and I have not had time to do much. My other tires were trashed so I picked up 4 - 39.5" Super Swampers for $50. They are only going to be temporary, but for $50 they will work. Also my fuel pump when out, so I spent the weekend fighting 15 years of Michigan rust to remove the gas tank, rear bumper, and rusted through receiver. Well I ended up getting the bumper removed, and the fuel tank dropped. I am in the process of cutting a access hole in the floor of the Suburban so I can access the fuel pump a lot easier if needed again. I am going to make a hinged access panel to cover the hole. I am also considering swapping in a 40gal fuel tank depending on the cost. Next is to grind off the rusted bolts so I can remove the receiver and the rest of the bumper brackets. Then I can mount my other bumper on it (pics of bumper are in the first 2 pages I think).
Pic with Swampers mounted
I HATE rust!!!!!!!!!!!!!
Pic with Swampers mounted
I HATE rust!!!!!!!!!!!!!
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