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Premium Member
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189 Posts
Discussion Starter #1
I only just reconditioned my handbrake unit on the espace 1.9 earlier this year. It’s the single unit type which controls both sides.. not the type with cable splitter on it or mechanisms on the hub.

I cleaned gunk out the motor, greased inside and put in some replacement used cables. Was fine all summer. Now its not been releasing fully on the left side. When the handbrake is off, this wheel only has one rotation freely, rather than the 2.5 rotation on the other side.

So to check if the caliper was seizing I drove using the brake normally came back to carpark and jacked it up with engine running so as not to switch on handbrake. Still partially seized.. so the caliper has a problem. I fitted brand new caliper, which fixed the seizing after driving, but made no difference to the handbrake not fully releasing it. So in the meantime I have removed the cable from the binding side so my wheel isn’t binding. Works ok on other side for now.

Now I am puzzled as what parts to order next, new cables or a used unit with used cables. I cant see any problem with the cable visually, but hard to tell obviously till I remove the handbrake unit And if the cable was damaged.. i.e. stretched.. then surely this should affect only its ability to engage the handbrake ? If the cable works to the point it can engage the caliper spring fully.. then it should be fine for releasing it ? Its not the caliper.. I test the spring and it works fine.

So would anybody know what fault would cause the electronic handbrake to only partially release the calliper spring on one side ? I guess it has to be some problem inside the handbrake unit ?
 

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Super Moderator Technical Supremo Platinum Member
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22,564 Posts
That sort of EPB unit should "self centre"
Each cable is attached at opposite ends of a motor driven screw so that when operated, screw shortens and pulls cables.... IIRC that mechanism all floats.
Could be sticking in the box I suppose ?

Normally I'd say binding on EPB caliper would likely be that the lever is sticking.
I know you have swapped caliper but check levers are free and that they have similar movement when EPB on. And return fully to stop.

Hydraulic issues are possible, the footbrake piston not retracting properly? Again, swapping the caliper should have fixed that if it were in caliper.
Not unknown for hoses to collapse internally and trap pressure in. But would have thought that would still show binding with the cable off.

Cables jamming is another favourite ?

Not much I'm afraid but may direct thoughts.

Further thought... The EPB unit cable connections are to the emergency release at one end and an adjustable "screw" at other.
When you swapped cables etc, did you set that screw to same distance it was?
I'm wondering if the floating mechanism is off centre so that is affecting movement, not allowing one cable to return fully ?
I got a manual somewhere for the single cable version and there is a setting dimension for that... dunno if it would be the same but I'll have a look.
 

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Premium Member
Joined
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189 Posts
Discussion Starter #3
That sort of EPB unit should "self centre"
Each cable is attached at opposite ends of a motor driven screw so that when operated, screw shortens and pulls cables.... IIRC that mechanism all floats.
Could be sticking in the box I suppose ?

Normally I'd say binding on EPB caliper would likely be that the lever is sticking.
I know you have swapped caliper but check levers are free and that they have similar movement when EPB on. And return fully to stop.

Hydraulic issues are possible, the footbrake piston not retracting properly? Again, swapping the caliper should have fixed that if it were in caliper.
Not unknown for hoses to collapse internally and trap pressure in. But would have thought that would still show binding with the cable off.

Cables jamming is another favourite ?

Not much I'm afraid but may direct thoughts.

Further thought... The EPB unit cable connections are to the emergency release at one end and an adjustable "screw" at other.
When you swapped cables etc, did you set that screw to same distance it was?
I'm wondering if the floating mechanism is off centre so that is affecting movement, not allowing one cable to return fully ?
I got a manual somewhere for the single cable version and there is a setting dimension for that... dunno if it would be the same but I'll have a look.
checked the lever, it was fine and the new caliper works fine, definitely the unit.

Off course forgot about programming settings.. If they are handy..thanks.. but no hurry .. no MOT till March. just aiming to sort before it gets too cold to work outside. Will try and plug into the unit and see what I can set. Previously had left the fitting part to the garage when it was done as didnt have my diagnostic "paperclip" with me then cough, cough.. >:)

Dont think it was the cable fitting.. once they were fitted, it seemed like there was only one way it could be done...It seemed like they were re-fitted just as they came out. but still could be. Could be that floating catch..remember when putting it together wondering if it might slip a little inside the unit, but I though nah.. renault surely couldnt design anything that flakey.. :|
 
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