Starting T-Type After LONG Term Storage

[GNRick]

Vacuum or hydroboost brakes could also save your life. But others will disagree.

 

[SCOOBY DOO]

The PM will continue to be a headache. Throw vacuum on it and call it a day.

 

[IrvJr]

I went vacuum and now I never have the fear each time i hit the brakes if the lights going to come on or if i wont have brakes.

 

[87_TX_T-Type]

Well it looks like the vacuums are the more vocal majority.

I've seen MANY different posts while searching vacuum setup threads. Is there a definitive or at least current parts list?

Kirban sells two vacuum kits (rebuilt boosters) for $350 & $400 (w/ and w/o the pedal). Not that I have any issue with Kirban, I've given them plenty of $$ thus far, but are there options from the local autoparts store?

 

[IrvJr]

I would just find a vacuum pedal and swap it then buy a dual diaphram booster and master cylinder. Wish i knew the model to use, im sure many would work but i think the B body's are bigger. Hopefully someone with more knowledge will chiime in with those parts. But i did the swap and it was fairly easy and straightforward.

 

[RmvBfrFlght]

As Irvjr posted there is a larger Caprice booster that some have used. A search here should turn up the information.

The other way to go is to purchase a '87 Buick Regal vacuum booster and M/C for a regular 'ole N/A Regal. Still need the pedal for it, but they pop up in the classifieds on a regular basis.

RemoveBeforeFlight

 

[87_TX_T-Type]

I'll look into the Caprice booster.

From what I've read, like you sai

As Irvjr posted there is a larger Caprice booster that some have used. A search here should turn up the information.

The other way to go is to purchase a '87 Buick Regal vacuum booster and M/C for a regular 'ole N/A Regal. Still need the pedal for it, but they pop up in the classifieds on a regular basis.

RemoveBeforeFlight

I'll look into the Caprice booster.

From what I've read, an '87 Regal non-turbo set up should work: master cylinder, 9" booster, booster to firewall seal, vacuum hose, check valve, and modified vacuum block. Either buy a different brake pedal, or modify the existing one.

RE: Vacuum block, since I'm no longer using the EGR, can't I just use that connection?

What about the BRAKE light on the dash? Is it only connected at the combo/prop valve, or do I need to do something special with the existing PowerMaster wiring?

Thanks guys. Big help. I'm feeling a lot better about making the switch.

 

[1986 Buick GX1]

When I did the vacuum conversion in the late '90's I took everything out of an '86 Monte SS. It uses a dual diaphragm booster that works well tee'd into the PCV line.
It was a little spongy at first, that's when I learned the importance of bench bleeding the M/C as pumping the pedal doesn't push the piston to the end of the stroke which leaves a little air in the end.
I'm set up more towards auto X, and have never tried launching at more than 5 psi, so take it for what it's worth.

The light in the dash only hooks to the prop/ combo valve. Just tape up the P-M connector.

Added photo.

 

[87_TX_T-Type]

The light in the dash only hooks to the prop/ combo valve. Just tape up the P-M connector.

Hmmmm... that's not a good sign, since the prop/combo is new, and the light is still on. I'm getting fluid to the rear brakes, so it shouldn't be closed.

I think I might try the following setup.
http://www.autozone.com/brakes-and-...n-brake-power-booster/725705_0_8550_3386_7192

It's for a 1990 Caprice, re-manufactured by Cardone, which is the same brand that Kirban sells, except this one is a 10.75" dual diaphragm. $163 isn't bad at all.

There is one WITH a vacuum switch, and one WITHOUT a vacuum switch. The one without the switch is about $20 cheaper. I presume since the car never had vacuum brakes it should need a vacuum switch. ???

 

[1986 Buick GX1]

Hmmmm... that's not a good sign, since the prop/combo is new, and the light is still on. I'm getting fluid to the rear brakes, so it shouldn't be closed.

The way I understand it, if the rear line leaks the switch piston/ plunger moves toward the rear turning the dash light on.
When the rear line is repaired it may be necessary to loosen a front bleeder and stomp on the brake pedal to return the piston/ plunger to the center.
I had to do this on an old ford truck after a rear cylinder leak, but maybe with a new prop/ combo valve it comes in the middle.
If the dash light stays on with the wire disconnected from the prop valve the wire may be shorted to the body somewhere.
If the dash light goes out when the wire is disconnected, the piston/ plunger may be off center.
It may take some experimenting loosening a bleeder front and rear to get it back in the middle.

There is one WITH a vacuum switch, and one WITHOUT a vacuum switch. The one without the switch is about $20 cheaper. I presume since the car never had vacuum brakes it should need a vacuum switch. ???

I didn't add any switches. The only ones needed on the pedal are the brake light switch and the one to disengage the cruise and they're already there, so I'm not sure on that one.

 

[RmvBfrFlght]

The park brake pedal also has a switch to turn on the Brake light.

The factory method of resetting the differential pressure brake switch is to stand on the brake peal.

RemoveBeforeFlight

 

[87_TX_T-Type]

Thanks for all the help guys. I received a Cardone 10.75" dual-diaphragm vacuum booster for a '90 Caprice yesterday, and managed to get it fitted (just barely) today. The bottom right edge of the booster is just barely touching the top of the wheel well covering (circled in yellow), so I don't think I could go any bigger without some modification.

Screenshot_20170924-232108_resized

• 87_TX_T-Type
• Sep 25, 2017

Plus, none of the various DIYs mentions some of the smaller, yet time consuming, issues one might face doing this job.

In addition, I needed to temporarily remove then reroute some of the grounding against the firewall (green circle), and the wiring harness for the bundle of cables going to the relays on the driver's side fender (in purple) had to be removed/discarded to push the wiring loom down far enough to get the booster in. Plus the vacuum line to the cruise control (red) will have to be rerouted a bit, and the various line that were right above the Power Master had to be moved up more. Same goes for the throttle cable, which had just enough slack to get the booster under it (although it might be better under).

Then there was this little bastard lock washer.
View media item 463This holds on a wiring harness inside the car on the lower left stud of the Power Master adapter place as it comes though the firewall. It didn't want to screw off, so it required the coaxing of a foot-long, very skinny, common screwdriver to pry up the tabs, and a pair of long needle nose pliers with a 90* bend at the end.

I am NOT looking forward to removing the pedal. Any advice is appreciated.

What's also odd is that most vacuum conversions state that the booster arm needs to be connected ABOVE the existing PM point on the brake pedal. However, the new booster arm seems aligned about a 1/2 inch below the existing point. Hmmm...

 

[mr84ss]

Your pictures not showing up on my end. When i did my brake conversion, taking the driver seat out helps alot. At the top of the brake pedal i put some paper towel in the path where the bolt goes thru so i can tell when its aligned correctly. For me it was hard to see though the maze of wires and the awkward postion laying under the dash but that helped alot

Sent from my LGMS631 using Tapatalk

 

[RmvBfrFlght]

What's also odd is that most vacuum conversions state that the booster arm needs to be connected ABOVE the existing PM point on the brake pedal. However, the new booster arm seems aligned about a 1/2 inch below the existing point. Hmmm...

Yes, it should be below the PM pickup point. This is for power brakes. Manual brakes have the pivot point above the PM pickup point. In the picture the upper pedal is a PM unit with the PM stud cut off. Then a hole drilled (too high) for a manual setup.

The lower picture is a standard power brake (vacuum) pedal. The stud is for the power brake booster push rod. With the hole above it the factory location for a manual brake setup.

RemoveBeforeFlight

 

[Gary Durden]

87-TX-TType, I think I would have sent my PM to Richard Clark for a rebuild. I had many Turbo cars and never had a serious problem with the PM. Seems like you have to go through a lot of headaches for a different brake system. Good luck with the install.

 

[87_TX_T-Type]

87-TX-TType, I think I would have sent my PM to Richard Clark for a rebuild. I had many Turbo cars and never had a serious problem with the PM. Seems like you have to go through a lot of headaches for a different brake system. Good luck with the install.

Was not aware of that, so...

Anyway, the vacuum build is not actually that bad, and relatively cheap at $150. I would much rather have the peace of mind and reliability of the vacuum brakes that their prevalence implies. I've been told several times that the brakes on this car were temperamental since day one (which is reflected in searches of this board). So basically I'm enduring a small headache now instead of several big ones, or worse, later. After all, the PM is a more complex and expensive system.

 

[87_TX_T-Type]

Making progress...
Painted the booster, received the master cylinder, and mounted everything up. MUCH easier routing the various cables the second time around - nothing binding. Bolting it up under the dash still wasn't fun, but easier this time around.

Only had to move one grounding wire from the firewall to the driver's fender under one of the relays. (Hopefully that is sufficient.) The brake lines required some gentle finessing to line up with the MC, but did so without crimping. (Yes, I still need to bench bleed the MC.)

So now my question is about sourcing vacuum.

Booster1

• 87_TX_T-Type
• Sep 26, 2017

As you can see the EGR is deleted, and the vacuum hose (red line) simply runs to a check valve (?) "T" toward the back of the block (circled in yellow). At the T, one end goes into a small plastic line that routes under the blower motor on the passenger side. The other end is a small plastic line that disappears under the windshield wiper motor.

Two Questions:
1) Since the EGR is deleted, is there issue with running a second T and line to the brake booster?
2) Are those other lines (under the blower & wiper motor) still needed now that the EGR is gone? (My ignorance, I don't know what they do.) I don't want to "split" the vacuum too many times, and create extra points of failure should one of the lines leak in the future.

Oh, one more thing for people doing this setup in the future. This setup just barely clears the hood when closed. I'm pretty sure the hood blanket is touching the top of the MC.

 

[87_TX_T-Type]

I found the vacuum schematic on my computer, and partially answered my own question.

Of the two vacuum lines that "T" off the EGR vacuum line; one goes to the HVAC and the other to the cruise control. That makes sense given their locations.

I'm going do a little more research, but go out on a limb and assume it is okay to pipe the brake booster into these lines. My logic being the HVAC/Cruise have a check valve and shouldn't draw too much vacuum. Plus when the brake booster is operating, the cruise should not be since they have opposing functions. (i.e. I'm not setting the cruise while braking.) I doubt I'll be fiddling with the HVAC while braking too.

Sound reasonable?

 

[IrvJr]

No. you need a bigger vacuum line than that. T off the pcv line or get a new distribution block with the extra tap for vacuum brakes.

 

[87_TX_T-Type]

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