FrenchyFred Posted March 7, 2017 Share Posted March 7, 2017 Hi everyone,I got an old Susuki DR 125S from a friend 6 months ago and I have the following problem. (Please keep in mind: this is my first bike and I'm a real, real rookie...)Everything was working fine when one day, I was biking, I ran out of fuel and suddenly the front break got stuck. In the sense that I couldn't move the bike anymore and there was constant pressure on the front break coming out of nowhere. In my right hand I could feel that the break was very "stiff" (usually I can push it a lot). It was like it was constantly "on" and breaking by itself. No idea if this has any link with me running out of fuel or a weird coincidence?At some point it unstuck by itself. Don't ask me why or how.So I decided to have a look... (this is where it gets funny)I took off the 2 bolts on the calliper of the front break and managed to remove the 2x pads quite easily. They looked ok but the inside of the calliper was real, real dirty. I started cleaning it with hot water and soap and gave it a good elbow grease. I also put some DW40 in there to clean it all. It was looking much better but the piston (there is only one by the way) was still dirty so I looked online and they advice to pump the break to make the piston stick out so you can clean the outside.I did this. The piston sticked out. I cleaned it.And now, impossible to move the piston back in. Like it doesn't move AT ALL and it stays completely out.I have no idea what to do... Should I look at the break fluid level? Should I bleed the system? Is it normal and I need special tool?Any advices would be absolutely amazing.Thank you!Fred. Quote Link to comment Share on other sites More sharing options...
Westbeef Posted March 7, 2017 Share Posted March 7, 2017 No to worry, be very careful now though you've used wd40 - you shouldn't use that on your brakes at all. For pushing the pin back in you needed to open the reservoir on the top of the handle bars to push it back in. A little bit might squirt out and the fluid is nasty stuff so stick a rag around it to catch any overflow. Have a watch of this it's very useful for exactly what you wanna do"> Quote Link to comment Share on other sites More sharing options...
FrenchyFred Posted March 7, 2017 Author Share Posted March 7, 2017 Thanks! Sounds easy. Apart from the fact that the 2 screws on the liquid reservoirs are F.... so I need to find a way to un-screw them... Fun times.I did watch that (great) video a lot and followed everything he said but he didn't have any issue with putting back the piston in which is why I came here 2 quick questions while I figure how to open the break liquid reservoir:- Why does opening the break liquid reservoir help? What's the "scientific" reason behind this?- Why shouldn't I have use Wd40? Was that a major mistake? Thank you! Quote Link to comment Share on other sites More sharing options...
Westbeef Posted March 7, 2017 Share Posted March 7, 2017 Thanks! Sounds easy.Apart from the fact that the 2 screws on the liquid reservoirs are F.... so I need to find a way to un-screw them... Fun times. Quick question while I figure that out: why does opening the break liquid reservoir help? What's the "scientific" reason behind this?Thank you! The fluid is under pressure, it has nowhere to go when you try to push it back in. The reservoir being open allows the fluid to go somewhere. Also I'm serious WD40 on your brakes can be a real issue I'm not sure what you should do about that. Hopefully someone else will be over soon to say what you should do. Quote Link to comment Share on other sites More sharing options...
FrenchyFred Posted March 7, 2017 Author Share Posted March 7, 2017 ok! Makes sense.To be clear I didn't put any WD40 on the pads! Only on the piston and inside the calliper. The pads were removed at this point. Still a f**k up I guess? Quote Link to comment Share on other sites More sharing options...
MR_W Posted March 7, 2017 Share Posted March 7, 2017 If pads weren't in and it's dried out the braking surfaces will be fine. Quote Link to comment Share on other sites More sharing options...
Tango Posted March 7, 2017 Share Posted March 7, 2017 I'd suggest popping the caliper piston out completely (put something underneath to catch the fluid) and give it a real good clean.......replace the seals......and then put some Red Rubber grease onto the seal before you put the piston back in. Also check that the caliper moves ok on the mounting plate......The pins and boots that it moves on should be in good condition and lubed up with more Red Rubber grease...... Obviously you need to get the screws out of the reservoir cap first.......you may need to drill them out if the heads are really chewed up...... Quote Link to comment Share on other sites More sharing options...
Lumor_uk Posted March 8, 2017 Share Posted March 8, 2017 wd40 is fine to clean with the pads removed. all excess wiped dry. Quote Link to comment Share on other sites More sharing options...
FrenchyFred Posted March 8, 2017 Author Share Posted March 8, 2017 Thanks a lot everyone. Super helpful. It's raining like crazy here so I will try everything tomorrow.Keep you posted! Quote Link to comment Share on other sites More sharing options...
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