The brakes will do the same thing they do when the engine stalls when you have a vacuum booster...they will work...but they are hard to push and worse than manual brakes but stoppable....An oil cooler is DEFINATELY a good idea with this swap!!....I'm a little lost on the snap ring thing myself...

That small reservoir is an accumulator which still provides fluid and assistance for the master cylinder even if the engine stalls.
Depending on the reservior one can expect a couple of pedal throws before the fluid is gone.
Safety feature designed into every unit. Some have these internally.

http://partimages.genpt.com/partimages/769990.jpg

Here is a NAPA picture of a Chevy booster, looks identical except it doesn't come with the plate with studs. The push-rod seems to match the Post 2001 Superduty style as well.

I am really intrigued with the hydraboost set-up. I ditched my vacuum booster and converted to manual brakes since I have to remove my valve cover fairly frequently. This set-up restores the power brakes and gives room for valvetrain service.

I am sorry if I am posting too many pictures or asking too many questions, but my favorite junkyards do not have the larger F450+ trucks or really anything newer than 2000, especially Superduty trucks with diesels. The yards that do have the newer vehicles are not the u-pull-it, but rather "we pull it for you and charge an arm & a leg".

So I am just trying to figure out all my options when I go and hit up the yards.

Josh


Josh

eBay - but then again it is MUCH easier to find one off a post 2001. As I said - from what I have seen they are the same F-250 thru F-450 or 550 on the post 2001's.

Finding one of the older F-450's is tough!

Any problems running a hydroboost with the 2wd Ford Thompson pump?

Josh

Hey, Bullitt, keep asking questions! I'm taking notes!

One thing I am not clear on. I have a 76 w/vac assist, front discs, rear drums. Is my master cylinder what I need? I don't quite get the discussion about proportioning valves and discs in the rear.

My impression is that I am OK with my MC because I am keeping my drums.

Sorry if this is a redundant question.

i'm not sure on the prop vavle, and someone will correct me if i am wrong, but i dont think you need aa prop valve if you are running all discs, or all drums. i believe you only need a prop valve if you are running discs and drums.

You will be ok with your proportioning valve but you will need the 78 master cylinder as the bolt spacing on the 78 mc will bolt up perfect to your hydroboost the 76 will not it is 3/16'' too narrow when it comes to spacing.

thanks for clearing that up ;)

every hydroboost has a large snap ring on the back side of it that keep the bolt from backing off. Once you flip the plate and put the large lock nut in place install the snap ring back in the groove it came from.:-jammin




And yes my mistake I meant the post 2001 trucks have a metric spacing not the pre 2001 trucks.:)



Well you guys can get a reman hydroboost from RockAuto that is for a 1990 F-SuperDuty for 138.00 if you are having a hard time finding them where you live. But out here they are common and cheap!8D

Come on guys keep the input coming! This thread could be useful information later on!

I should be heading to the junkyards Monday, but I think I might be looking at more Chebby's than Superduty's. All in all, the boosters look (according to NAPA pictures) exactly the same regardless of the vehicle type. The "iffy" part would be mounting the booster to the firewall and hooking up the pressure lines. I assume it may be possible the Chevy lines use a different style than the Fords, i.e. JIC adapters versus Boss and etc.

Josh

Just make sure you are looking at "newer" chebby's.

From what I recall the diesel trucks and blazers had hydroboosts back to the early 80's. Youd want something in the mid to late 90's at the earliest.

The early chevy hydroboost units have the same thread sizes and stud spacing. But the mounting plate is different and the pushrod is way too short.All these units are made by Bendix and are allmost the same.

Hmmm - that just fired up the old noggin.

I think I might just fabricate a new mounting plate rather than making an adapter to go from the bolt pattern of my hydro to the bolt pattern on the firewall.

I'll have a look at this tomorrow hopefully.

I was thinking of shortening the studs on the original SD Plate...then make a plate that matches the firewall holes....use spacers or make a spacer block to adjust the length of the rod to the correct length...bolt the original plate studs to the adapter plate and the fabbed plate to the firewall.

So, if I am getting this right, (chances are I am not because I am a bit lost in this thread,) one could get an early chevy boost set up and modify it to fit our firewall, and then simply lengthen the pushrod to compensate for pedal height? Or is the pushrod you are referring to the pushrod between the master and the hydroboost?

That was in essence what I was looking at and how most people do it. My "spacer" was going to be a solid aluminum billet and I was looking at through bolting both (hydroboost and firewall). Based on bolt locations, etc that gets kinda tricky - so I will either re-drill the hydroboost mounting plate to the firewall pattern and then use a machined spacer and through bolt, or just make a new plate for the hydroboost and use a machined spacer and through bolt.

You got it right the 1st time - we are referring to the pushrod that connects the pedal to the hydroboost unit.

The post 2001 Superduty and Chevy units need the push-rod longer?

Wow, when I swapped in my manual brake 1985 Ranger m/c I had to shorten several inches off of the pushrod, just guessing but I would reckon the pushrod is about 6 inches long (ok no laughing).

I am also seeing two techniques for the swap. One is bolting the booster directly to the firewall and the other it reusing the vacuum booster bracket.

How much harm is there is just drilling new holes in the firewall for whatever pattern the booster studs happen to be instead of making adaptor plates and such.

I called my local junkyard and a used Chevy booster is $18, plus $5 for each pressure line.

Josh
Josh

2001 hydro needs a SHORTER rod - hence the spacer on the firewall. I'm not positive about chebby boosters - but it looks like they need longer.


You can very wll punch new holes in the firewall. I am running a spacer because I have a 2001+ hydro with the longer pushrod and I don't want to mess with shortening the rod or moving my pedal closer to the seat (just gets annoying haivng to lift your foot that much higher to hit the brake pedal).

Ahhh... I see said the blind man.

Looks like the Chevy booster I posted has a pushrod as long as the 2001 Superduty.

As for my pedal, I couldn't possibly come up anymore, the brakelight bracket is almost right against the stop. Unless One were to drill a new hole in the pedal for the pushrod bolt.

Josh

you can always weld a piece of 1/4" (maybe 3/8" - however thick the pedal is) piece of plate on the front of the pedal with a hole in it is well. This would allow for the longer pushrod and no spacer...

If it is any help to anyone I called the local ford dealership you can get the F-450 mounting bracket new for 32.00 plus 9.00 for the nut.

Figures - stealership price = $32 for a $1 piece of steel with some holes in it. Not that I would ever waste $$ on buying something from a stealership that I can make myself, but for others it might work;)

so can you use the stock p/s pump or do you have to use a pump off the f-450?

You have to use a P/S pump that is has two returns. One comes back from the P/S box and the other from the hydroboost. If you are getting stuff from a donor truck, it's best to pull everything including the P/S pump. Get the hoses, brackets, and P/S pump. That's what I did when I pulled mine out of an '88 F450. The F-450 M/C is too much and I will be switching back to a '78 F-350 M/C sometime soon. I hear the F-250 M/C works well though.

You don't need a new pump. You can do 2 things get the plastic reservoir with 2 return ports or just put a T fitting on the stock return line. GM used the T fitting and ford used the dual return reservoir. The choice is yours.

Excellent write-up gashog. I think I'll do the hydroboost to the crew before I'm done with it.

Still just did not have the right pedal feel, well I got that fixed!I replaced the front two rubber lines and the rear rubber brake line with custom made stainless braided line. huge difference in response and pedal feel! I had all the lines custom made at a local truck service center. The really expensive part was the rear because the hose is part of the line block that bolts to the axle housing. I ended up reusing the stock block but machining and threading it to accept the new line. All in all for 127.00 i'm happy!

I ended up having to shorten the push rod about 1" or so. I just cut it in the middle, beveled it and welded it. No damage to the unit.

I see you are working on a 2wd. I have a 79 4wd crew and my booster looks like this


Attachment 204146.


I see the rod coming out of your booster is straight. Would this be a problem with the F450 hydroboost booster??

Vacuum boosters bolt onto a firewall bracket which then gets bolted to the firewall. The bracket has it's own rod assembly that attaches to the pedal. The booster pushrod is bolted to the bracket rocker.

Josh

I might be misunderstanding your statement.

The booster bolts to the bracket and the booster pushrod bolts directly the pedal in my application. No rocker bracket or pivot point.

My 68 bronco has a pivot point behind the booster bracket.

So looking around today I found a complete Hydroboost F450 Setup but it is a diesel. I assume that the booster and lines are the same but what about the pump. Do you think It might be able to be retrofited onto a 460 with L&L Brackets???

I also pulled mine out of an F-450 and it was a direct bolt-in, except that I made brackets to mount the booster to the firewall and had to rebend the lines a bit. I currently have a 351M and the pump bolted right on my current P/S bracket. I don't know anything about the L&L bracket, but I would expect the pump would bolt up fine to it too.

The pump will bolt right up. Also the picture looks like a 1/2ton booster those have a pivot point but none of the 3/4 or 1 ton use a pivot point.

I did my hydroboost conversion last year. Theres pics in my gallery under the 78 SuperCab. Mine was a 2000 or 01 F-350 setup. Only difference is I had to fab a simple adapter bracket. Watch your power steering gear box cause it might start leaking due to the extra pump pressure and 30 year old seals. Mine did then I effed it up figuring out how to replace the seal.

Edit:
Also the brake pedal is in the original location and the cruise control plug thing at the end of the booster rod fit like a glove. Its interesting to note that the SD pump has the same bolt holes and pulley shaft diameter as the old trucks.

You must have gotten a screaming deal on your parts. I have not been able to find anything close to that price her locally.

What would everyone expect to pay for a complete, working unit off of a 92-97 F450. The hydroboost booster, brackets, all the lines, and the power steering pump?? I have found a few but they seem WAY over priced!!!

depends on where you buy from or what deal you come across. Sometimes you will luck into a good deal on ebay or at a local pick n pull, other times you'll have to pay retail for reconditioned or new parts.

It often depends on your time line. I scoured eBay for a few weeks before pulling the trigger on my stuff. I got 2 complete units (hydro, master cyle and hoses) off 2001 trucks for about $125 shipped. I've seen people pay a lot more and a couple people pay a lot less. It's the luck of the draw with your timing and location really!

Did yours have the pump and all the lines for $125.00?? Also the F450 seems to be a bit more rare so maybe that is why it is more money. Most local yards want 125.00-150.00 for just the booster. No lines or pump.