I knew saying Old Thar CRDe would make part resellers more confused; instead, I asked for a Scorpio 2.6L part.
BHPian Blooming_Flower recently shared this with other enthusiasts.
Interesting Findings While Working on The Thar CRDe.
We all know how Thar was conceived and created as an amalgamation of various components of MM540, Bolero, and Scorpio. Although on paper, Thar CRDe has a total of 3 face-lift models there exist many production variations since the beginning. E.g. Thar with or w/o factory-fitted AC, with or w/o auto-locking hub, with or w/o ABS (different from 1st Oct, 2019), with MLD without MLD (difference from 2015 F/L) etc. However, there are basically two distinct models of Thar CRDe, one is from 2010-15, and another from 2015-20. Also, in multiple media and ownership reviews, it’s been agreed that the 2015 model is merely a facelift of cosmetic changes with existing mechanicals (except MLD at the rear axle). But there are some major mechanical changes I discovered during the following sequence of events.
Let’s come to the point without digging much into recent history. Last week, I was travelling to Delhi for some work, which is about 80km distance from my place. After driving the first 50km on the highway the brake pedal travel increased a bit and it started to feel spongy. When I reached the destination the brake pedal was almost touching the floor and brake bite was occurring with distinctly two-step travel of the pedal. After checking the entire brake line for possible leakage, it was diagnosed that the master cylinder was the culprit. I was a bit taken aback by such a major failure in a car with less than 30k km on odo. Indeed, the weakest links in a master cylinder are a few rubber seals that may have gone bad!
Well, let’s change the master cylinder. The mechanic went to source the part in a prominent auto parts market in Delhi. As a common practice, he showed the stock M/cyl. and the seller assured us that he will source it within one hour from other suppliers. All that he needed to get a master cylinder of ‘Old Thar CRDe’. So, after waiting around 2.5 hours finally, the replacement part arrived. But the surprise was lurking before starting the fitment! The diameter of the M/cyl and the push rod slot of the primary piston didn’t match the booster. We inspected the replacement part minutely. Yes, it was different! Surprisingly both the master cylinder was Bosch make and carried the same part number by Bosch embossed on the body (M7102309)! As the time was almost past 9 pm and I had to return, I asked the mechanic to fit the stock M/cyl. and bleed the brake so that I can drive the car at a slow speed to reach home after all. The brake was biting albeit with a long and spongy pedal travel; my conviction was telling me at least the primary cylinder is working, maybe some rubber seal on the secondary piston is kaput causing this two-step behaviour of the brake pedal. I drove very slowly keeping sufficient distance from the vehicle in front and reached home safely. 80km without traffic (60 km of which is 4-6 lane highway) for 3 hours!
The same night I started studying the Mahindra parts catalogue in detail. And finally, after an ample amount of minute scrutiny, I found a few things.
- Mahindra uses Bosch-make master cylinders and booster assemblies for old gen Boleros, Scorpio and Thar.
- Basically, there exist three types of master cylinders by Bosch for Mahindra cars with the same part number embossed on them (M7102309), vide picture. The basic difference is the diameter of the cylinder. They are 23.81 mm, 25.40 mm and 26.99 mm.
- Mahindra OE and Bosch aftermarket parts are the same; only the internal part numberings by Mahindra and by Bosch differ for the same product.
- At least two of them have been used in a single vehicle alternately with minor facelifts.
- For Thar CRDe (2011-15), this is 25.40 mm and is common with Bolero 1st, 2nd Gen, Bolero Pickup, and camper. The part number by Mahindra is 0606AAB01480N Bosch is 0204712859 (with the reservoir) and 0204712869 (w/o the reservoir).
- For Thar CRDe non-ABS 2015 F/L model the part is exactly same with Scoprio 2.6 Slx (2006-2008) model (26.99 mm M/cyl). The part number by Bosch is 0204318029 and by Mahindra is 0607AA0820N.
I also referred to the Bosch after-market brake parts catalogue to re-confirm whether the part is common with Scorpio 2.6 Slx. PDF shared as an attachment. Do search for T029 (short code for the same part). Yes! This is a common part!
All is well as of now. I went to the local automobile market to source the part. No surprise that the local Mahindra showroom had not a single piece in their inventory, and they even confirmed it is not even available in nearby SVCs. They were also clueless about when to receive the part if I place an order with them. Also, it is imperative that they can’t sell the parts directly to the customer without opening a job card, and this will eventually prompt me to get the job done at their workshop paying a hefty price for labour. After all, I am not satisfied/confident with the workmanship of the Mahindra-authorized SVC so far from my previous service experience.
As usual, in the auto parts market, even the prominent retailer asks, “Master cylinder for which vehicle?” (Calling out the part number directly often doesn’t work with them). I knew saying Old Thar CRDe would make them more confused; instead, I asked for Scorpio 2.6. I got negative answers from all of them. One referred to another seller and this cycle went on for 10 times at least! Even one of them called the Bosch dealer (M/s Tulsi Lok) only to find a big NO again! Seeing me at my wit’s end, one seller promised to source it from Delhi, but he was unable to promise any timeline for delivery, and even mentioned I may have to pay over the MRP in case he manages to get it! I took their contact number and left the place. While I was about to return a big truck messed up the busy city traffic at the signal near the market and I had to take a u-turn. Finding a parking spot is difficult there, yet I was determined to scavenge the market once again. I parked a car a bit far and went on asking each shop in a row, one by one! After going through this searching ordeal for 2.5 hours there was some silver lining on the horizon. The owner of a small shop took me to the 1st floor (basically his storage area) and pointed me to a bunch of old Bosch and TVS Girling M/cyls. boxes parked at a corner. He himself went to search through the lot, and as I almost memorized the part number I shouted “Mil Gya”, and took out the old box (refer pic.) myself. It was the required M/cyl, from December 2017 batch. Well, it is completely out of the question to demand a part with a newer manufacturing date when the part is itself an endangered species according to the market scenario. I collected the part, few bottles of DOT4 brake oil, and went to the local mechanic for fitment.
(Thar used DOT3 brake and clutch fluid from the factory; I don’t know how much cost Mahindra saved through it while selling the Thar at a very high price than the cost involved in production and R&D combined. This high pricing factor was also repeatedly acknowledged in the forum by the father of Thar, late BD Sir himself)
While driving I was thinking this major mechanical change in the brake system has not been covered anywhere. In fact, the entire brake system along with the hand brake was changed in the 2015 F/L Thar. When the 2015 F/L model hit the market BD sir was no longer associated with Mahindra. Otherwise, I believe he would have pitched in somewhere in the forum.
This also made me recall umpteen complaints on poor braking from pre-F/L Thar owners and BD sir referring to Rajith from B’lore for improving the brake system. IIRC, Rajith also used a Scorpio tandem booster and master cyl. assembly and tweaked the LSPV setting to secure better braking performance. I have no idea whether this discussion caught the attention of the then Thar CRDe F/L development team, and perhaps, they silently implemented it without explicitly mentioning anything about this, unlike the MLD!
Till then, I hardly had any idea what surprise over surprise was waiting for me!
I asked the local mechanic just to change the master cyl. and bleed the brake as the diagnosis has already been done. He opened the stock master cyl and tallied it with the one I brought. He exclaimed ‘Ditto’! I was just waiting for the job to be over within 30 min. After 45 mins, I found the head mechanic and his assistants struggling to fit the brake tubings to the M/cyl. I stopped them and asked not to force-fit the tubes lest the threads get damaged beyond repair. I asked them to unbolt the newly fitted M.cyl from the brake booster. I took two of them side by side and tried to find differences. They were looking the same, bearing the same part number. I measured the dia. with vernier callipers, and they were exactly matching. Thereafter, I inspected the tubing fitment holes with my mobile flashlight! Voila. The stock one needs convex tubing fitment while the one I brought needs concave tubing!
Let me highlight a few facts about standard brake tube flares.
There are two types of standard brake-pipe flares. One is known as ‘double’ flare (SAE standard), and another is ‘bubble’ type, aka (ISO/DIN std.) Thar CRDe uses the ‘bubble’ type brake line flare. I was baffled by the fact that with the same part number Mahindra/Bosch used two different standards of fitment!
Again, went to the market and after much effort sourced two pieces of brake tubes with ‘double’ flare end fitments. But what I need to have is something else that no standard hose/ brake tube manufacturer will do ever! For the fitment with the new M.cyl I needed a ‘double’ flare at the M.Cyl side and a ‘bubble’ flare at the brake line wheel-splitter side.
This can be achieved in two ways–
- Get a roll of 3/16” brake tubing of sufficient length and make the required flare at the ends using a flaring tool.
- Take two different end fitments and join them with the tube by brazing.
Although any sane brain would have preferred the first one for neater and cleaner execution, I had no choice other than going with the second one due to a lack of resources to execute the first one in my city.
Okay. It was almost evening time by then and sourcing a welder may be difficult after that. I myself went to a known welder without delaying a minute and asked him to cut a single stock tubing to get two ‘bubble’ flare end fitments and braze each one of them at the end of the newly sourced tube. Once it cooled down, I checked for any possible leakage in both pipes by blowing through them and holding another end with a finger. All seems to hold well as of now!
I came back to the mechanic and asked him to fit those ASAP and bleed the brake. The bleeding at the M/Cyl and all 4 wheels’ ends consumed almost 1L of DOT4 oil. Finally, the brake was working as usual with a proper pedal response. Ordeal over!
That night I myself executed a teardown of the old M/Cyl and my conviction came true. A single rubber seal on the secondary piston was worn out causing all the drama! I cleaned the inside of the M/cyl and observed no such scratches to discard it completely. Now, I am in the process of sourcing a repair kit to keep it as a working spare.
However, sourcing the right kit is very difficult. M/Cyl repair kits are of 3 types viz.
- Only rubber seals and O-rings
- Minor repair kit (contains rings, locks, and the primary piston)
- Major repair kit (contains primary, and secondary pistons and all the rubber kits and locks).
So, either I need to source 1 or 3 to repair the old M.Cyl. The cost of the third is more than 75% of the entire M/Cyl price. So, going with the 1 will be the most VFM option to repair while sourcing the first one is a gamble!
After all these findings, only one question comes to my mind—Why Mahindra why? Why so many variables and no standardization? At the end of the day, the brunt is borne by the customer only! Why is no steady inventory maintained at the dealer level too?
Recently, while going through Thar 2020 review thread I noticed a few members expressing how Mahindra is an ever-evolving company implementing smaller changes (not always positive, e.g. deleting a few existing features) to the vehicles with the passage of time. Well, it is not a great engineering example to follow so many standards for a single vehicle. Although it can be termed continual improvement in the field of engineering, sometimes it is not welcome!
Mahindra must not take their customers for a ride; nor all customers can, or have the time to delve deeper into such a level to get the work done. We love jeeps, we love Mahindra cars. But the niggles, and the trauma of executing proper repair work are immense to dent the love for sure.
Keyword: My frustrating experience changing the brake master cylinder on my Thar