Hydraboost??

[FLYNAVY53]

I finally got around to completely gutting the brake system on my '72 C20 Suburban daily driver. The only thing thats still original is the pedal. I used a new factory booster with a Baer 1 1/8" "Remaster" master cylinder and adjustable prop. valve. Lines are all stainless with -3 fittings and braided flex lines at the calipers. Calipers are Wilwood D52 replacement 4 piston units front and rear and Im running discs off a mid-80's K20.

After bleeding and bedding the pads, the system works great, and stops the 3/4 ton truck on a dime, but the pedal feel/effort is terrible. You really have to stand on it, but when you do, she stops in a hurry. It took me a minute to figure it out, but I think the issue is the fact that my 6.0L LS motor is pulling little to no vacuum at idle. At 1200 RPM, I'm seeing 20, but at idle it barely registers on my vacuum gage.

This brings me to the Hydraboost.....not an inexpensive proposition, but if this will get me the pedal feel I'm looking for, whats another $1.5K down the rabbit hole right??? I know there are plenty of guys on here running the system, I just wanted to hear your thoughts on how well it works, and how much of a pain in the ass the install is.....also, what brand/manufacturer do you recommend?

Thanks for the help!!

[Hydratech®]

http://www.hydratechbraking.com/GM_67-72_CK.html

You can continue to use your existing Baer ReMaster - won't even have to touch brake fluid if you leave the brake lines connected to the MC during installation.

Pedal feel?

Here is a quote from this thread:


Paul, could NOT be happier with your braking system, perfect easy install, and the braking is phenomenal .. the setup feels as close to a production performance car as you could possibly get, and Jim was awesome to deal with


http://www.lateral-g.net/forums/showthread.php4?t=50526&page=3


Ok, now wait for it....

Here come the DIY'ers that will tell you to spend $50 on a junkyard unit, "wrap it in Velcro LOL" and then just "toss it up on the firewall" :wedgie:


NOTE: We are beyond backed up with e-mail at present, so do please call Jim: http://www.hydratechbraking.com/contact.html (live time clock on this web page for call hours)

[Later-A-body]

So is the pedal travel an issue, or the effort required? It sounds like the system itself is functioning properly since it stops well. As for hydroboost, I had it on my car for about 8 years. Yes it stopped great, but the pedal was very hard and had little travel which is something to get used to. I also did not like the lack of modulation. The one thing that finally got me to remove it was the noise. Some systems are very quiet, some not so much. I never had any problems with air trapped in the system, but it will have that inherent whining sound. I also did not like the pedal feedback when you really stood on the pedal hard. It is very expensive to set up, and there is a lot of plumbing to run. I finally decided to go to a manual system due to the simplicity.

[FLYNAVY53]

Paul, I appreciate the input...I specifically plumbed the Baer master with flex lines to the front distribution block so that I could remove/service the booster without breaking into the system. Ill give Jim a shout this week to pick his brain about a potential set up for my truck.

[FLYNAVY53]

So is the pedal travel an issue, or the effort required? It sounds like the system itself is functioning properly since it stops well. As for hydroboost, I had it on my car for about 8 years. Yes it stopped great, but the pedal was very hard and had little travel which is something to get used to. I also did not like the lack of modulation. The one thing that finally got me to remove it was the noise. Some systems are very quiet, some not so much. I never had any problems with air trapped in the system, but it will have that inherent whining sound. I also did not like the pedal feedback when you really stood on the pedal hard. It is very expensive to set up, and there is a lot of plumbing to run. I finally decided to go to a manual system due to the simplicity.


I appreciate the input....the issue is pedal effort....pedal travel is minimal. I've seriously considered going to a strait manual set up for the sake of simplicity, but my concern is that the pedal effort would be as much, if not more than as it currently sits given that I'm trying to stop a 3/4 ton truck (I may be way off on that assumption as well). Obviously I would need to get a brake pedal appropriately ratio'd for a manual set up, in addition to possibly replacing the master with a smaller bore unit.

The Hydraboost is appealing based on the many positive reviews I've read, but as you stated, its not cheap, and there is additional plumbing involved. The noise doesn't so much bother me as between the lumpy cam, loud mufflers, minimal sound deadening, and the covered wagon ride of a 45 year old truck, I doubt any whine from the unit would significantly degrade the already "visceral" driving experience that is my truck (only my dog likes it as much as I do!).

My big concern is that I have a truck that stops extremely well...at this point I'm after pedal feel. I don't want to sink a bunch of money into a system that is equally numb, just at a different effort level.....if I'm going to have high effort, I might as well go strait manual brakes and at least have solid pedal feel.

Again, I welcome input from any and all who have gone the hydraboost route...I'm not interested in the junk yard DIY system....I'm talking about a full tilt, engineered, aftermarket hydraboost system. I've also considered a vacuum accumulator or an electric vacuum pump. I welcome input on any of these systems. I don't want to half-ass anything, I want something functional and reliable.

Thanks very much for any and all input!!

[Hydratech®]

The hydroboost itself does not create any noise. It is a PS pump producing excessive flow (or damaged with a chipped internal vane) that creates hydraulic PS system noise...

Now take a look at the only vacuum pump that actually works half way decently (in my opinion):

http://www.mpbrakes.com/accessories/vacuum-pump-kits/electric-vacuum-pump-kit-ac9001k

You will also have to add a vacuum reserve tank:

https://www.summitracing.com/parts/sum-g1464/overview/

And then wire it all in and plumb it all in. Add up those costs and hassles.

We have spoken with hundreds of customers that have gone this route initially, but still find that a few repeated stops (as in rush hour traffic) runs the system out of vacuum at times providing a scary "my heart skipped a beat and I also greased the seat" unexpected experiences. The hydroboost systems are consistent in their response, whether you are going 25 or 125+ MPH. We are speaking of retrofitting a 2017 GM 2500 / 3500 series factory Bosch produced hydroboost unit into your application, of course done with some really cool aftermarket engineering, class, and style...

:cheers:

[FLYNAVY53]

Paul, is the pushrod removable from the Hydratech booster like it is in a factory vacuum booster? I ask because when I installed the Baer master cylinder, I had to pull the pushrod out of the booster and grind about 1/4" off of it in order to get the clearance recommended by Baer between the pushrod and master cylinder piston.

Thanks,
Greg

[Hydratech®]

Hi Greg - are you using the MC in late model / short MC pushrod mode *OR* are you using it in the early / long deep MC pushrod mode? You can view the differences at the bottom of this web page listing (scroll all the way down to see the images):

http://www.hydratechbraking.com/GM_67-72_CK.html

Baer had a severe problem with pushrod lengths / depths initially when they first came out with the ReMaster, and they actually had us send one of our short rod (late model) (shallow pocket) systems out to them so that they could work with it (as our MC pushrod lengths have been nailed down to a science / perfected over 17 years in the making). The Baer engineers called me and we discussed the issues, and it turns out Raybestos was supplying them with the incorrect piston sets causing the MC pushrod depth issues. This was approximately two years ago, and I believe Baer has it nailed down nowadays. IF you are using it in the late model / short MC pushrod version, that means that you are using the slug / plug / spacer bullet that inserts into the backside of their MC (which is setup for the deep hole / long MC pushrod version out of the box)(then supplied with the spacer plug to convert it for use with the late model / short MC rod). If you are running the long rod early design, then we have total proven out plug n play. By contrast, if you are running the late / short version, it would be best to extract the Baer supplied spacer bullet and grind / machine it if / as needed as opposed to modifying the MC pushrod installed into our brake units.

All of the above being said, let me know if you are running the long rod or short rod version. Our MC pushrods are not removable (well, at least not easily), so this IS a key discussion to the success of your installation.

:cheers:

[RSX302]

I very much enjoy my hydroboost setup. I did have the same issue with the long mc pushrod too as it was dragging the rear brakes. Using Wilwood 1 1/8 tandem master.

I couldn't get any manual system to work on my brakes to my liking. Brakes are Wildwood Superlite 6 -13" front, Dynalite 4 -12" rear. (BP-20 Pads)

With the hydroboost, all good now and I enjoy the solid pedal feel. I can keep right on the edge of wheel-lock with minimal to moderate effort. Not too touchy during race events.

On a side note, I do run large Toyo R888's all-around. Im sure it would be a different story if I had smaller, harder street rubber.

[FLYNAVY53]

Hey Paul,

First, I greatly appreciate the continued responses/answers. My wife works in marketing so I'm well versed in what a time suck it can be answering every internet forum thread.

As far as the Baer Remaster goes....I just ordered it and put this brake system together a month or so ago, so its a relatively new build master cylinder. At the moment, Im running the late model/short pushrod version. I have the supplied billet spacer slug installed in the Remaster. At the time that I installed the master with the replacement factory booster, I found that running the deep hole set up was way off, but running the shallow/late model plug actually slightly preloaded the booster when it was fully bolted up. I purchased the Baer tool for measuring the pushrod length accurately and ended up grinding .25" off the pushrod in the factory reproduction booster to achieve the specified clearance between the plug in the master cylinder and the pushrod....I don't remember what it is off the top of my head but it was something minimal.....010" maybe....I distinctly remember being surprised how much I had to grind off the pushrod to achieve what amounted to "paper thin" clearance between the pushrod and the slug in the master cylinder.

Anyway, if you have specifically tested your set up with the Baer Remaster, and know the tolerances are good, it appears I can either go with the long or short rod by simply removing the billet spacer/plug....? I'm not married to either set up, just looking for something that will work as advertised, so let me know whether to go with the long or short pushrod set up and Ill give you guys a call tomorrow.

Thanks,
Greg

[Hydratech®]

If your truck rolled into my shop, we would go short / late rod on the brake unit - P/N 3038. Why? It would provide what we feel is the best option, as it leaves you open for a larger range of possible future MC choices AND it would allow the Baer spacer bullet to be machined down just a hair (if needed) instead of the brake assist unit's MC pushrod. If you screw up royally, Baer can always send you a replacement spacer bullet (even though I can't envision that happening). We have been serving customers running the Baer Remasters for plenty enough time now to feel comfortable either way, though I personally say "short rod"...

One more thing - be careful using those MC depth / pushrod gauges. They would be perfect if we were working with flats (flat ended MC pushrod and flat ended MC pistons). What isn't being taken into account entirely too often is the radius of the pushrods and the MC piston receiver radius measurements. One small difference in a radius can result in a whopping difference. If we do find preload, we actually prefer to sneak up on the clearances when needed by starting with a minor preload, and then carefully machine / grind the forward end of the spacer bullet down only a few thou at a time while testing the MC live against the brake booster. Once the preload is gone, we then typically remove about .015 - .020" further for additional clearance to compensate for thermal expansion / guarantee a full state of MC piston release under all possible circumstances. Lots of MC's these days have drilled / simple tapered pushrod receivers instead of the more expensive radius machining which causes preload in some cases even though the depth gauges say all is well. Our MC output pushrods are stout at 3/8" diameter, and we have been fine tuning the MC pushrod lengths for years against every possible MC combination we have encountered.

[FLYNAVY53]

Paul....just placed the order per your recommendation....I look forward to getting the system installed. The wife took the Suburban to work on Friday and nearly plowed into the back of someone because she's used to the hair trigger brakes in her Mini Cooper and wasn't expecting the amount of pressure required to get the current system to bite.