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Volvo R brakes on 240 pedal feel issues

stick70 said:
I've had no pedal issues with my r brakes all around and mustang master :e-shrug:

I will say my pedal is a little touchy. Not lock the brakes up touchy, but someone that hasn't driven the car will find the pedal sensitive.
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Same experience. Ended up switching to the earlier, smaller, single-diaphragm booster and think it is just right with the mustang master and caddy calipers.
 
stick70 said:
Do you know approx what years I should be looking at for this?
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I got mine from Rockauto, A-1 CARDONE 535890, that was for a 1977 240. Looks like they are currently out of stock though. Maybe one of the fellas that services the wanted adds on here will have one on their shelves?
 
stick70 said:
I've had no pedal issues with my r brakes all around and mustang master :e-shrug:

I will say my pedal is a little touchy. Not lock the brakes up touchy, but someone that hasn't driven the car will find the pedal sensitive.
Click to expand...

Mine is the opposite of that. I have the new mustang master here with the bigger bore but have yet to install. Im still in the middle of a custom wooden barn door build. Hoping to get to the swap in a few days.
 
When I tried using a larger that stock master cylinder (Ford F-Series) on my 88 765 with Jumbo brake upgrade the brake pedal was nearly impossible to press, the pedal was rock hard. I installed a 2000 Ford Ranger master cylinder with 1.0625 inch bore and it was a good option. A 1/16 inch difference in bore size makes a huge difference. I also learned that the 700/900 cars with Jumbo Brakes used a brake pedal with a different ratio. So matching the brake pedal ratio to the master cylinder is a good idea.
 
And now the results:

I am at fault for both issues. I clearly did my math wrong on the extension of the push rod, it was about 15mm short and I bought the wrong master cylinder. I bought a SVT when I should of bought the GT one. All is fixed and brakes are great and feel the same as they did when I bought the car back in 2007
 
Glad to hear that man, I'm sure you're happy it wasn't something more labor intensive.

When available could you please share the part number for the GT Master cyl you purchased?
 
MDVLN said:
Glad to hear that man, I'm sure you're happy it wasn't something more labor intensive.

When available could you please share the part number for the GT Master cyl you purchased?
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Been bugging me for about a year now. I wish the 5mp and under squeal would go away.

The part I bought is a Dorman M390185 LINKY
 
stick70 said:
I've had no pedal issues with my r brakes all around and mustang master :e-shrug:
I will say my pedal is a little touchy. Not lock the brakes up touchy, but someone that hasn't driven the car will find the pedal sensitive.
Click to expand...

Marvelous3 said:
The rod length is important to get right. If you haven't you need to replace the adjustment screw on the end of your brake booster rod. The stock rod isn't long enough to work with the mustang master.
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Have R calipers f/r in my ’93 960 sedan with 330 mm R-discs, stock R brake pads with Mustang MC including rod extension. Together with replacing the MC the rod was extended. So what symptoms occur when f.i. the rod is just too short. The brakes are pretty touchy. Slowing down by just touching the brake pedal instantly activates the safety-belt locks. Took some time to get used to that at first. But on the other hand when I brake firmly at around 60 mph, the braking effect is only average. At a certain point deceleration does not increase when the pedal is pressed even harder. The brake force remains the same. Locking the wheels is absolutely impossible, far from triggering ABS. Dangerous situation. Vacuum issue? Using Chrysler E-throtltle. No leaking tubes.
 
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Sounds like brake pad knock back to me.

@rijk, make sure to clean your hub surfaces and that there is no runout on your brake rotors.
 
Hank Scorpio said:
Honestly sounds like the pushrod is set to long.
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Thanks. I'm going to check that.

Harlard said:
Sounds like brake pad knock back to me.

@rijk, make sure to clean your hub surfaces and that there is no runout on your brake rotors.
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Have left nothing to chance: Meticulous revision of all four calipers, new R-pads, new R-discs, new hubs, new SKF wheel bearings. No runout, non abnormal pedal feeling.

I am open to other suggestions.
 
Pad knockback won't give you those symptoms. What pads are you using? I hate to ask, but did you make sure they were in the right way around? What you're describing is exactly what I'd expect if you have the pads inside out...

Ignoring the stupid question, have you bedded the pads / rotors yet?

If the calipers were junkyard parts, did you check that the pads move freely? It's not uncommon (I have bought ~ a dozen of these so far) for there to be corrosion behind the steel pad-stopper plates in the caliper; this can result in the plate being forced inward and blocking / cocking the pad as it moves towards the rotor. Likewise did you verify that all of the pistons move freely? I've also had more than a few arrive with pistons siezed in the bore due to corrosion.
 
DrZiplok said:
Pad knockback won't give you those symptoms. What pads are you using?
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OEM R pads. No fancy stuff.

I hate to ask, but did you make sure they were in the right way around? What you're describing is exactly what I'd expect if you have the pads inside out...
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With inside out you mean the friction material is facing outwards instead of towards the disc???

Ignoring the stupid question, have you bedded the pads / rotors yet?
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I ignore that question :-)

If the calipers were junkyard parts, did you check that the pads move freely? It's not uncommon.
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No junkyard parts. Bought second hand from reliable party. Although in good working order all four calipers were overhauled for safety reasons with new OEM parts (pistons,seals etc)
 
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