Brakes from Geo Metro problem (1 Viewer)

[american outlaw]

Hey,

I have a 1962 with disk brakes up front and the previous owner installed Geo Metro brake booster/cylinder.

The brakes started having problems so I replaced the calipers and rebuilt the wheel cylinders in back. Then I replaced the booster and master cylinder.

After bench bleeding and then bleeding the wheels, the pedal just feels limp when the vehicle is running. Is this normal feeling for this brake combo? Did I grab the wrong year booster and cylinder? anything I could look at to get the brakes feeling good? Last thing I wanna do is find myself lodged in the back of a minivan

 

[B y r o n]

Since Geo Metro parts are not the norm around here, pictures of what you're working with would help.

 

[american outlaw]

Since Geo Metro parts are not the norm around here, pictures of what you're working with would help.

Ill have to get the photos tonight after work.

But what the previous owner said was that with the factory soft top body the normal cruiser boosters/cylinders collided with the original carburetor.

Would it be better to find a different narrow bodied booster to put in instead? I am unsure of what options exist with the limited space

 

[DeskJock]

Ill have to get the photos tonight after work.

But what the previous owner said was that with the factory soft top body the normal cruiser boosters/cylinders collided with the original carburetor.

Would it be better to find a different narrow bodied booster to put in instead? I am unsure of what options exist with the limited space

I'm struggling to understand this:

"But what the previous owner said was that with the factory soft top body the normal cruiser boosters/cylinders collided with the original carburetor."

 

[3_puppies]

it is not the soft top body, it is the firewall rib, pre mid year 1970 brakes were manual and the rib ran close to the master.
adding a booster the rib is in the way or use a spacer which moves everything forward with clearance issues
IIRC the Geo Metro booster is small and doesn't take up much space

 

[american outlaw]

it is not the soft top body, it is the firewall rib, pre mid year 1970 brakes were manual and the rib ran close to the master.
adding a booster the rib is in the way or use a spacer which moves everything forward with clearance issues
IIRC the Geo Metro booster is small and doesn't take up much space

yea the rib is cut... I just assumed it was from having a slightly different body than the other land cruisers. didnt know that was just a pre 70s thing. the more ya know!

 

[DeskJock]

Ah. Got it. So - if you want to mount a booster, you need to cut the fire wall and install a plate to move the booster/ master closer to the fire wall.

 

[Grayscale]

Sounds like a brake bleeding, or brake shoe-adjustment issue.
I dig those early rigs, yours has the smaller cut-out for the doors? Nostalgia, or tech, pics appreciated.

 

[3_puppies]

Ah. Got it. So - if you want to mount a booster, you need to cut the fire wall and install a plate to move the booster/ master closer to the fire wall.

it is either cut the firewall brace for clearance or use a spacer to move the booster out past the rib, other issue is the brake and clutch master are closer together than the later rigs so a large diameter booster has clearance issues

 

[45Dougal]

One alternative would be to fit a remote servo, and use the original master cylinder at the bulkhead.
Not very common now, but used to be a thing on small British cars in the 70s such as the Mini.

 

[american outlaw]

Sounds like a brake bleeding, or brake shoe-adjustment issue.
I dig those early rigs, yours has the smaller cut-out for the doors? Nostalgia, or tech, pics appreciated.

If I get home before the sun goes down, I will get ya some photos!

I was thinking it was my rear drums not being adjusted properly. The Geo metro cylinder has 2 ports from the chamber, one goes directly to the rear brakes. The other goes directly to the front (no proportioning valve). Would bad rear brakes cause it to have a squishy pedal? My 1980 doesnt have any rear brakes in it currently and the pedal still feels great whenever I press it.... who would think that factory Toyota parts would work better than a GEO metro

 

[american outlaw]

I found photos from the previous owners build on IH8Mud, so I have some old photos to share of the brake booster (too busy for my own good after work ) So, no adaptor. The rib was cut and holes were made for bolts to fit in. The top hole is plugged and the two side ports go to their respective axles.

currently my build has a weber carb, and the plugged up vacuum port goes directly to the booster. Like in the last comment, I really think its the rear drums brakes not being adjusted properly. Ill have to take the the drums off and get that going proper and report back tomorrow

 

[Mark W]

Since your firewall brace is already cut, you can use an FJ40 booster. The drum brake booster is significantly smaller than the disc brake booster. It is very likely that you will have some very slight clearance concerns with the intake. But it is usually so slight that simply slipping a washer or two at the most over the two inboard studs of the booster will cant it enough to clear without causding any other fitment problems.

Mark...

 

[american outlaw]

Imma try to salvage my cheap geo metro parts first! Since I have disk brakes up front, ill need a disk brake booster and thatll add size

 

[pb4ugo]

Problems with bleeding rear drum brakes is a constant issue and has been covered at nauseum. Below is probably the most recent thread.

1973 brake issues

Brake pedal always goes to the floor even after bleeding and seating brakes. I have drum brakes all the way around. New everything at each wheel, all replaced with new not rebuilt. I have a new master brake cylinder too. All the parts are from CCOT. I have seated all the drum brake shoes and...

forum.ih8mud.com

 

[Grayscale]

If the pedal was tight before the replacement parts and rebuild, then you probably can restore function to that point. That said, I wonder about that plug on the second fitting for the front hydraulic circuit?

It gets tricky adjusting the cylinders on the rear so that you have dragging shoes on both sides, especially when you can't recenter them with hydraulic pressure. It also gets tricky getting every bit of air out. My experience has been frustrating, but, I think that I'm past the learning curve. Depending on what squishy means, check out this similar thread, good advice there, and a few different perspectives on the issue: 1973 brake issues - https://forum.ih8mud.com/threads/1973-brake-issues.1345268/

Can you pump-up the brakes to get the brake pedal to sit higher when depressed? Or does the pedal sink to the floor, while it is depressed? Or does the pedal just go to the floor without resistance?

 

[american outlaw]

If the pedal was tight before the replacement parts and rebuild, then you probably can restore function to that point. That said, I wonder about that plug on the second fitting for the front hydraulic circuit?

It gets tricky adjusting the cylinders on the rear so that you have dragging shoes on both sides, especially when you can't recenter them with hydraulic pressure. It also gets tricky getting every bit of air out. My experience has been frustrating, but, I think that I'm past the learning curve. Depending on what squishy means, check out this similar thread, good advice there, and a few different perspectives on the issue: 1973 brake issues - https://forum.ih8mud.com/threads/1973-brake-issues.1345268/

Can you pump-up the brakes to get the brake pedal to sit higher when depressed? Or does the pedal sink to the floor, while it is depressed? Or does the pedal just go to the floor without resistance?

I think i can restore it to where it was. since all the parts are new or rebuilt.

The feel of the pedal is solid without the booster. But when the vehicle is idling the pedal just gives little to no resistance when i put my foot on it. It just has very little resistance until it hits the hard stop at the end of the throw. Ill give the 1973 brake issues post a good read. and then just spend a day or two pumping and bleeding brakes until it all feels okay

 

[Shark56]

Did it work fine before your issues to cause a rebuild?
If it did then my guess is you need to adjust the rear drums tighter.
That linked thread has a lot of info.

 

[3_puppies]

Since I have disk brakes up front, ill need a disk brake booster and thatll add size

you can use a drum booster just fine with front discs, no need to run a bigger booster than needed.

wonder if the new master is for a disc/drum, the rears need a residual valve
versus a disc/disc setup

 

[Mark W]

Imma try to salvage my cheap geo metro parts first! Since I have disk brakes up front, ill need a disk brake booster and thatll add size

Actually no, you do not need the disc brake booster. Most people ci\onsider it a bit over boosted with the factory disc brakes. The drum brake booster works great with disc brakes. a mini'truck or an FJ80 MC is shorter than the original unit too. And Al, not Fe.

Mark...