View Full Version : MBM Brake Booster Master Combo

03-06-2016, 02:50 PM
I have the MBM brake booster kit PBUF5772 for my 60 Sunliner and I'm having trouble fitting the firewall bracket to the booster itself.
Here is a photo of the complete kit.

http://i1382.photobucket.com/albums/ah278/thomas_smith14/Mobile%20Uploads/brake%20kit_zpsgxmsvrue.jpg (http://s1382.photobucket.com/user/thomas_smith14/media/Mobile%20Uploads/brake%20kit_zpsgxmsvrue.jpg.html)

In the next two photos I'm trying to show that the bracket won't mount to the booster with the threaded push rod centered. When connected it just pulls the rod down and way off center. It looks like it would work if the threaded rod was much shorter. Is it supposed to be adjustable? Am I supposed to cut it to fit? What am I doing wrong here?

http://i1382.photobucket.com/albums/ah278/thomas_smith14/Mobile%20Uploads/booster%202_zpstfqqeotl.jpg (http://s1382.photobucket.com/user/thomas_smith14/media/Mobile%20Uploads/booster%202_zpstfqqeotl.jpg.html)

http://i1382.photobucket.com/albums/ah278/thomas_smith14/Mobile%20Uploads/booster_zpsmhc57b0c.jpg (http://s1382.photobucket.com/user/thomas_smith14/media/Mobile%20Uploads/booster_zpsmhc57b0c.jpg.html)

03-07-2016, 12:39 AM
...When connected it just pulls the rod down and way off center. It looks like it would work if the threaded rod was much shorter. Is it supposed to be adjustable? Am I supposed to cut it to fit? ...Yes, and I'm surprised they didn't tell you in the instructions. I like your pictures but I need to see how long your clevis (eyelet) is. Show one with a scale next to it.

Leave the jam nut on but back it off as far as you can. Hold the clevis (eyelet) up to it and eyeball where you want to cut the booster rod.

If it builds your confidence to cut a little at a time, ok. By the time you get close, the distance will be the same.

Use the jam nut to 'chase' the end of the thread once it's cut.

It's very important you bench bleed your M/C before mounting it. Did they supply a plastic bench bleed kit? I mount my M/C on my vise and use a #4 Phillips screwdriver in the hole as I progressively stroke the piston. Start with short, slow strokes then as the bubbles come out go deeper. After about twenty times, the bubbles will stop.

I don't like the 'closed ports' method. - Dave

03-07-2016, 08:58 PM
The only instructions I could find were on the MBM site. Those instructions assume you already have everything put together. They do provide a bench bleed kit. I was just trying to get everything mounted for fitment. I'm sure I'll probably have to make some brake lines also. The clevis is 1 1/2". Here's the pic.
Looks to me like I'll have to cut quite a bit of the booster rod for it to be centered when connected. The clevis will be right up against the boot.

http://i1382.photobucket.com/albums/ah278/thomas_smith14/Mobile%20Uploads/pin_zpssdgdgfzo.jpg (http://s1382.photobucket.com/user/thomas_smith14/media/Mobile%20Uploads/pin_zpssdgdgfzo.jpg.html)

03-07-2016, 09:37 PM
Yep, that's ok and that's how mine is. I have the same clevis you do, the short 1-1/2" version. They offer a longer one, but you already have the correct clevis.

Go ahead and start cutting... - Dave

03-07-2016, 09:59 PM
Ok will do. I'll let you know how it goes. What's the best way to mount the combination valve?

03-07-2016, 10:20 PM
The best way is to mount the combination valve on your fender apron, then pipe to it. That gets it out of the way when you work on you engine or spark plugs.

I liken this to your electrical and plumbing components in your house.. Mount the fixtures and boxes FIRST, then wire or pipe to them. - Dave

03-11-2016, 08:43 PM
Here are a couple pics of it mounted up. The clevis is right up against the firewall but I don't think its applying any pressure. I think it will be ok? by the time I cut the pushrod so it would fit like this, there was no more room for a jam nut.

http://i1382.photobucket.com/albums/ah278/thomas_smith14/Mobile%20Uploads/mounted_zpsyonyuxox.jpg (http://s1382.photobucket.com/user/thomas_smith14/media/Mobile%20Uploads/mounted_zpsyonyuxox.jpg.html)

http://i1382.photobucket.com/albums/ah278/thomas_smith14/Mobile%20Uploads/mount_zpspvxxs4il.jpg (http://s1382.photobucket.com/user/thomas_smith14/media/Mobile%20Uploads/mount_zpspvxxs4il.jpg.html)

Joe Johnston
03-11-2016, 09:13 PM
Not real keen about it touching or the lack of a jam nut. Why not add a spacer and move it forward? Plenty of length on the mounting studs.

03-12-2016, 02:45 AM
Nice job, and neatly tucked in. Spacers or big washers behind the booster would be ok but really not necessary. Our Galaxie is the same. The booster rod cannot turn and neither can the clevis. Make sure your hardware is tight. Any flexing turns into 'soft brake pedal'. - Dave